Solutions

A solution contains non-volatile solute of molecular mass $M_{2}$ . Which of the following can be used to calculate the molecular mass of solute in terms of osmotic pressure ? [AIPMT/NEET 2002]
1. $M_{2} = (\frac{m_{2}}{π}) V R T$
2. $M_{2} = (\frac{m_{2}}{V}) \frac{R T}{π}$
3. $M_{2} = (\frac{m_{2}}{V}) πRT$
4. $M_{2} = (\frac{m_{2}}{V}) \frac{π}{RT}$
A solution has a 1 : 4 mole ratio of pentane to hexane. The vapour pressuress of pure hydro-carbons at $20 ° C$ are 440 mmHg for pentane and 120 mmHg for hexane. The mole fraction of pentane in vapour phase would be [AIPMT / NEET 2005]
1. 0.786
2. 0.478
3. 0.549
4. 0.200
A solution of urea (molar mass 56) boils at $100.18 ° C$ at atmospheric pressure. If $K_{f}$ and $K_{b}$ for water are 1.86 and 0.512 K $m o l a r i t y^{- 1}$ respectively, the above solution will freeze at [AIPMT / NEET 2005]
1. $- 6.54 ° C$
2. $6.54 ° C$
3. $- 0.654 ° C$
4. $0.654 ° C$
The vapour pressure of two liquids P and Q are 80 torr and 60 torr respectively. The total vapour pressure obtained by mixing 3 mole of P and 2 mole of Q would be [AIPMT / NEET 2005]
1. 68 torr
2. 20 torr
3. 140 torr
4. 72 torr
During osmosis, flow of water through a semi-permeable membrane is [AIPMT / NEET 2006]
1. from both side of semi-permeable membrane with unequal flow rates
2. from solution having lower concentration only
3. from solution having higher concentration only
4. from both sides of semi-permeable membrane with equal flow rates
A solution containing 10 g per $d m^{3}$ of urea (molar mass = 60) is isotonic with a 5% (mass by vol.) solution of a non-volatile solute. The molar mass $(i n g m o l^{- 1})$ of non-volatile solute is [AIPME/NEET 2006]
1. 350
2. 300
3. 250
4. 200
1.0 g of a non-electrolyte solute (molar mass $250 g m o l^{- 1}$ ) was dis-solved in 51.2 g of benzene. If the freezing point depression constant of benzene is $5.12 g m o l^{- 1}$ , thbe lowering in freezing will be [AIPMT / NEET 2006]
1. 0.5 K
2. 0.4 K
3. 0.2 K
4. 0.3 K
A 0.5 molal aqueous solution of a weak acid (HX) is 20 per cent ionized. The lowering in freezing point of this solution is $(K_{f = 1.86 K / m f o r w a t e r})$
1. 1.12 K
2. -0.56 K
3. 0.56 K
4. -1.12 K
A 0.020 m acqueous solution in an ionic compound $C o {(N H_{3})}_{5} (N O_{2}) C l$ freezes at $- 0.00732 ° C$ . Number of moles of ions which 1 mol of ionic compound produces on being dis-solved in water will be $(K_{f} = + 1.86 ° C / m)$ [AIPMT / NEET 2009]
1. 1
2. 4
3. 3
4. 2
A solution of sucrose (molar mass $342 g m o l^{- 1}$ ) has been produced by dis-solving 68.5 g sucrose in 1000 g water. The freezing point of the solution obtained will be $(K_{f} f o r H_{2} O = 1.86 k g m o l^{- 1})$ [AIPMT / NEET 2010]
1. $- 0.372 ° C$
2. $- 0.520 ° C$
3. $+ 0.372 ° C$
4. $- 0.570 ° C$
The van't Hoff factor i for a compound which undergoes dissociation in one solvent and association in other solvent is respectively [AIPMT / NEET 2011]
1. greater than one and greater than one
2. less than one and greater than one
3. less than one and less than one
4. greater than one and less than one
The freezing point depression constant for water is $- 1.86 ° C m^{- 1}$ . If 5.00 g $N a_{2} S O_{4}$ is dissolved in 45.0 g $H_{2} O$ , the freezing point is charged by $- 3.82 ° C,$ Calculate the van't Hoff factor for $N a_{2} S O_{4}$ . [AIPMT/NEET 2011]
1. 0.381
2. 2.63
3. 2.05
4. 3.11
$p_{A} a n d p_{B}$ are the vapour pressure of pure liquid components, A and B, respectively of an ideal binary solution. If $x_{A}$ represents the mole fraction of component A, the total pressure of the solution will be [AIPMT / NEET 2012 ]
1. $p_{B} + x_{A} (p_{B} + p_{A})$
2. $p_{A} + x_{A} (p_{A} + p_{B})$
3. $p_{A} + x_{A} (p_{B} + p_{A})$
4. $p_{B} + x_{A} (p_{A} + p_{B})$
Which of the following components can be used as anti-freeze in automobile radiators ? [AIPMT / NEET 2012]
1. Methyl alcohol
2. Glycol
3. Nitrophenol
4. Ethyl alcohol
$6.02 \times 10^{20}$ molecules of urea are present in 100 mL of its solution. The concentration of solution is [AIPMT / NEET 2013]
1. 0.1 M
2. 0.001 M
3. 0.01 M
4. 0.02 M
Of the following 0.10 m aqueous solutions, which one will exhibit the largest freezing point depression ? [AIPMT / NEET 2014]
1. $K_{2} S O_{4}$
2. $N A l_{2} {(S O_{4})}_{3}$
3. $C_{6} H_{12} O_{6}$
4. $K C l$
Which one of the following electrolytes has the same value of van't Hoff factor (i) is that of $A l_{2} {(S O_{4})}_{3}$ (if all are 100% ionised) ? [AIPMT / NEET 2015]
1. $A l {(N O_{3})}_{3}$
2. $K_{4} [F e {(C N)}_{6}]$
3. $K_{2} S O_{4}$
4. $K_{3} [F e {(C N)}_{6}]$
The boiling point of $0.2 m o l k g^{- 1}$ solution of X in water is greater than equimolal solution of Y in water. Which one of the following statements is true in the case ? [AIPMT / NEET 2015]
1. Molecular mass of X is less than molecular mass of Y
2. Y is undergoing dissociation in water while X undergoes no change
3. X is undergoing dissociation in water
4. Molecular mass of X is greater than molecular mass of Y
What is the fraction of the solute in a 1.00 m aqueous solution ? [AIPMT / NEET 2015 Re]
1. 0.0354
2. 0.0177
3. 0.177
4. 1.770
At $100 ° C$ the vapour pressure of a solution of 6.5 g of a solute in 100 g water is 732 mm. If $K_{b}$ = 0.52, the boiling point of this solution will be [AIPMT / NEET 2016 Phase-I]
1. $103 ° C$
2. $101 ° C$
3. $100 ° C$
4. $102 ° C$
Which of the following statements about the composition of the vapour over an idal 1 : 1 molar mixture of benzene and toluene is correct ? Assme that temperature is constant at $25 ° C$ . (Given,m vapour pressure data at $25 ° C$ , benzene = 12.8 kPa, toluene = 3.85 kPa) [AIPMT / NEET 2016 Phase-I]
1. Not enough information is given to make a prediction
2. The vapour will contain a higher percentage of benzene.
3. The vapour will contain a higher percentage of toluene
4. The vapour will contain equal amounts of benzene and toluene
If 5.85 g of NaCl are dissolved in 90 g of water, the mole fraction of NaCl is [AIIMS 2001]
1. 0.1
2. 0.2
3. 0.3
4. 0.0196
What will be the molarity of a solution containing 5 g of sodium hydroxide in 250 ml solution ? [AIIMS 2001]
1. 0.5
2. 1.0
3. 2.0
4. 0.1
If 5.85 g of NaCl (molecular weight 58.5) is dissolved in water and the solution is made up to 0.5 litre, the molarity of the solution will be [AIIMS 2002]
1. 0.2
2. 0.4
3. 1.0
4. 0.1
To prepare a solution of concentration of $0.03 \frac{g}{m l}$ of $A g N O_{3}$ , what amount of $A g N O_{3}$ should be added in 60 ml of solution [AIIMS 2002]
1. 1.8
2. 0.8
3. 0.18
4. None of these
How many g of dibasic acid (mol. wt. 200) should be present 100 ml of its aqueous solution to give decinormal strength ? [AIIMS 2003]
1. 1 g
2. 2 g
3. 10 g
4. 20 g
The molarity of a solution of $N a_{2} O_{3}$ having 10.6 g / 500 ml of solution is [AIIMS 2003]
1. 0.2 M
2. 2 M
3. 20 M
4. 0.02 M
Molecular weight of glucose is 180. A solution of glucose which contains 18 g per litre is [AIIMS 2004]
1. 2 molal
2. 1 molal
3. 0.1 molal
4. 18 molal
0.5 M of $H_{2} S O_{4}$ is diluted from 1 litre to 10 littres, normality of resulting solution is [AIIMS 2004]
1. 1 N
2. 0.1 N
3. 0.1 molal
4. 18 molal
An aqueous solution of glucose is 10% in strength. The volume in which 1 g mole of it is dissolved will be [AIIMS 2005]
1. 18 litres
2. 9 litres
3. 0.1 molal
4. 18 molal
When 1.8 g glucose dissolved in 90 g of $H_{2} O$ , the mole fraction of glucose is [AIIMS 2005]
1. 0.00399
2. 0.00199
3. 0.0199
4. 0.998
A 5 molar solution of $H_{2} S O_{4}$ is diluted from 1 litre to 10 litres. What is the normality of the solution ? [AIIMS 2006]
1. 0.25 N
2. 1 N
3. 2 N
4. 7 N
Normality of 2 M sulphuric acid is [AIIMS 2006]
1. 2 N
2. 4 N
3. $\frac{N}{2}$
4. $\frac{N}{4}$
What is the molarity of $H_{2} S O_{4}$ solution, that has a density $1.84 \frac{g}{c c}$ at $35 ° C$ and contains solute 98% by weight [AIIMS 2007]
1. 4.18 M
2. 8.14 M
3. 18.4 M
4. 18 M
Which of the following is a colligative property ? [AIIMS 2008]
1. Osmotic pressure
2. Boiling point
3. Vapour pressure
4. Freezing point
The vapour pressure of benzene at a certain temperature is 640mm of Hg. A non-volatile and non-electrolyte solid weighing 2.175 g is added to 39.08 g of benzene. The vapour pressure of the solution is 600mm of Hg. What is the molecular weight of solid substance ? [AIIMS 2009]
1. 49.50
2. 59.6
3. 69.5
4. 79.8
The average osmotic pressure of human blood is 7.8 bar at $37 ° C$ . What is the concentration of an aqueous NaCl solution that could be used in the blood stream ? [AIIMS 2009]
1. 0.16 mol / L
2. 0.32 mol / L
3. 0.60 mol / L
4. 0.45 mol / L
The osmotic pressure in atmospheres of 10% solution of cane sugar at $69 ° C$ is [AIIMS 2010]
1. 724
2. 824
3. 8.21q
4. 7.21
The molal boiling point constant for water is $0.513 ° C k g m o l^{- 1}$ . When 0.1 mole of sugar is dissolved in 200 ml of water, the solution boils under a pressure of one atmosphere at [AIIMS 2011]
1. $100.513 ° C$
2. $100.0513 ° C$
3. $100.256 ° C$
4. $101.025 ° C$
The freezing point of a solution prepared from 1.25 g of a non-electrolyte and 20 g of water is 271.9 K. If molar depression constant is $1.86 K m o l e^{- 1}$ then molar mass of the solute will be [AIIMS 2012]
1. 105.7
2. 106.7
3. 115.3
4. 93.9
Osmotic pressure of 0.1 M solution of NaCl and $N a_{2} S O_{4}$ will be [AIIMS 2012]
1. same
2. Osmotic pressure of NaCl solution will be more than $N a_{2} S O_{4}$ solution
3. Osmotic pressure of $N a_{2} S O_{4}$ solution will be more than NaCl.
4. Osmotic pressure of $N a_{2} S O_{4}$ will be less than that of NaCl solution
At $25 ° C$ , the highest osmotic pressure exhibited by 0.1 M solution of [AIIMS 2013]
1. $C a C l_{2}$
2. KCI
3. Glucose
4. Urea
Azeotropic mixture of HCI and water has [AIIMS 2014]
1. 84% HCI
2. 22.2% HCI
3. 63% HCI
4. 20.2% HCI
The boiling pointg of water $(100 ° C)$ becomes $100.25 ° C$ , if 3 grams of a non-volatile solute is dissolved in 200 ml of water. The molecular weight of solute is
$(K_{b} f o r w a t e r i s 0.6 K - m)$ [AIIMS 2015]
1. $12.2 g m o l^{- 1}$
2. $15.4 g m o l$
3. $17.3 g m o l^{- 1}$
4. $20.4 g m o l$
ASSERTION : Molecular mass of benzoic acid when determined by colligative properties is found high.
REASON : Dimersion of benzoic acid. [AIIMS 2010]
1. If both the assertion and reason are true and the reason is true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assetion.
3. If the assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : A mixture of cyclohexane and ethanol shows -ve deviation from Raoult's Law.
REASON : Cyclohexane reduces the inter-molecular attraction between ethanol molecules. [AIIMS 2011]
1. If both the assertion and reason are true and the reason is true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assetion.
3. If the assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : Use of pressure cooker reduces cooking time.
REASON : At higher pressure cooking occurs faster. [AIIMS 2013]
1. If both the assertion and reason are true and the reason is true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assetion.
3. If the assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : $C C l_{4}$ and $H_{2} O$ are immiscible.
REASON : $C C l_{4}$ is a polar solvent. [AIIMS 2014]
1. If both the assertion and reason are true and the reason is true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assetion.
3. If the assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : Isotonic solutions do not show the pnenomenon of osmosis.
REASON : Isotonic solutions have equalosmotic pressure. [AIIMS 2015]
1. If both the assertion and reason are true and the reason is true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assetion.
3. If the assertion is true but reason is false.
4. If assertion is false but reason is true.
Which of the following concentration factors is affected by change in volume or volume dependent ?
1. Weight fraction
2. Mole fraction
3. Molality
4. Molarity
A solution of $A l_{2} {(S O_{4})}_{3} \{d = 1.253 \frac{g m}{m l}\}$ contain 22% salt by weight. The molarity, normality and molality of solution is
1. 0.825 M, 48.3 N, 0.805 M
2. 0.805 M, 4.83 N, 0.825 M
3. 4.83 M, 4.83 N, 4.83 M
4. None
An X molal solution of a compound in benzene has mole fraction of solute = 0.2. The value of X is
1. 14.0
2. 3.2
3. 1.4
4. 2.0
5 ml of N HCl, 20 ml of N/2 $H_{2} S O_{4}$ and 30 ml of N/3 $H N O_{3}$ are mixed together and volume made to one litre. The normality of the resulting solution is
1. $\frac{N}{40}$
2. $\frac{N}{10}$
3. $\frac{N}{20}$
4. $\frac{N}{5}$
At $25 ° C$ , the density of 15 M $H_{2} S O_{4}$ is $1.8 g c m^{- 3}$ . Thus, mass percentage of $H_{2} S O_{4}$ in aqueous solution is
1. 2%
2. 81.6%
3. 18%
4. 1.8%
The molality of a urea solution in which 0.0100 g of urea, $[{(N H_{2})}_{2} C O]$ is added to $0.3000 d m^{3}$ of water at STP is
1. 0.555 m
2. $5.55 \times 10^{- 4} m$
3. 33.3 m
4. $3.33 \times 10^{- 2} m$
A 3.5 modal aqueous solution of methyl alcohol $(C H_{3} O H)$ is supplied. What is the mole fraction of methyl alcohol in solution ?
1. 0.100
2. 0.059
3. 0.086
4. 0.050
In which mode of expression of concentration of a solution remains independent of temperature ?
1. Molarity
2. Normality
3. Formality
4. Molality
The density of a solution containign 13% by mass of sulphuric acid is 1.09 g/mL. Calculate the molarity and normality of the solution
1. 1.445 M
2. 14.45 M
3. 144.5 M
4. 0.1445 M
Calculate the molarity of pure water (d = 1 g / L)
1. 555 M
2. 5.55 M
3. 55.5 M
4. None
20 ml of 0.02 M $K M n O_{4}$ was required to completely oxidise 10 ml of oxalic acid solution. What is the molarity of the oxalic acid solution ?
1. 0.1 M
2. 0.4 M
3. 1.0 M
4. 4.0 M
Find the molality of $H_{2} S O_{4}$ solution whose specific gravity is $1.98 g m l^{- 1}$ and 95% by volume $H_{2} S O_{4}$
1. 7.412
2. 8.412
3. 9.412
4. 10.412
Suppose 5 g of $C H_{3} C O O H$ is dissolved in one litre of Ethanol. Assume no reaction between them. Calculate molality of resulting solution if density of Ethanol is $0.789 \frac{g}{m l}$
1. 0.0856
2. 0.0956
3. 0.1056
4. 0.1156
Calculate normality of the mixture obtained by mixing 100 ml of 0.1 N HCl and 50 ml of 0.25 N NaOH solution
1. 0.0467 N
2. 0.0367 N
3. 0.0267 N
4. 0.0167 N
How many kilograms of wet NaOH containing 12% water are required to prepare 60 litres of 0.50 N solution ?
1. 1.36 kg
2. 1.50 kg
3. 2.40 kg
4. 3.16 kg
The volumes of two HCl solutions A (0.5 M) and B (0.1 M) to be mixed for preparing 2 L of 0.2 M HCl are
1. 0.5 L of A + 1.5 L of B
2. .10.5 L of A + 0.5 L of B
3. 1 L of A + 1 L of B
4. 0.75 L of A + 1.25 L of B
What weight of oxalic acid $(H_{2} C_{2} O_{2}, 2 H_{2} O)$ is required to prepare 1.000 mL of N / 10 solution ?
1. 9.0 g
2. 12.6 g
3. 6.3 g
4. 4.5 g
Which of the following units is useful in relating concentration of solution with its vapour pressure ?
1. Mole fraction
2. Parts per million
3. Mass percentage
4. Molality
Relation between the volume of gas (2) that dissolves in a fixed volume of solvent (1) and the partial pressure of gas (2) is ( $n_{1}$ = total moles, $K_{1} a n d K_{2}$ are Henry's constants)
1. $\frac{n_{1} R T}{n_{2}}$
2. $\frac{n_{2} R T}{K_{2} p_{2}}$
3. $\frac{n_{1} R T}{K_{2}}$
4. None of these
The pressure under which liquid and vapour can co-exist at equilibrium is called
1. Limiting vapour pressure
2. Real vapour pressure
3. Normal vapour pressure
4. Saturated vapour pressure
The vapour pressure of a liquid in a closed container depends upon
1. Amount of liquid
2. Surface of the container
3. Temperature
4. None of the above.
What is the concentration of $O_{2}$ in a fresh water stream in equilibrium with air at $30 ° C$ and 2.0 bar ?
Given, $K_{H}$ (Henry's Law constant) of $O_{2}$ = $2.0 \times 10^{- 3} \frac{m o l}{k g}$ bar at $30 ° C$ .
1. $8.736 \times 10^{- 3} \frac{g}{k g}$
2. $1.344 \times 10^{- 3} \frac{g}{k g}$
3. $24.04 \frac{g}{k g}$
4. $114.5 \frac{g}{k g}$
The solubility of $N_{2} (g)$ in water exposed to the atmosphere, when the partial pressure is 593 mm is $5.3 \times 10^{- 4} M$ . Its solubility at 760mm and at the same temperature is
1. $4.1 \times 10^{- 4} M$
2. $6.8 \times 10^{- 4} M$
3. 1500 M
4. 2400 M
Co(g) is dissolved in $H_{2} O$ at $30 ° C$ and 0.020 atm. Henry's law constant for this system is $6.20 \times 10^{4} M .$ Thus, mole fraction of Co(g) is
1. $1.72 \times 10^{- 7}$
2. $3.22 \times 10^{- 7}$
3. 0.99
4. 0.01
An unopened soda has an aqueous concentration of $C O_{2}$ at $25 ° C$ equal to 0.0408 molal. Thus, pressure of $C O_{2}$ gas in the can is
$(K_{H} = 0.034 \frac{m o l}{k g} b a r)$
1. 0.671 bar
2. 1.49 bar
3. 1.41 bar
4. 1.71 bar
A sample of air is saturated with benzene (vapour pressure - 100 mmHg at 298 K) at 298 K, 750 mmHg pressure. If it is isothermally compressed to one third of its initial volume, the final pressure of the system is
1. 2250 torr
2. 2150 torr
3. 2050 torr
4. 1950 torr
$H_{2} S$ is used in qualitative analysis of inorganic cations. Its solubility in water at STTP is $0.195 m o l k g^{- 1}$ . Thus, Henry's Law constant $(i n a t m m o l a l^{- 1})$ for $H_{2} S$ is
1. $2.628 \times 10^{- 4}$
2. 5.128
3. 0.185
4. $3.826 \times 10^{3}$
Pressure cooker reduces cooking time for food because
1. Boiling point of water involved in cooking is increased
2. Heat is more evenly distributed in the cooking space
3. The higher pressure inside the cooker crushes the food material
4. Cooking involves chemical changes helped byh a rise in temperature.
A solid dissolves in water if
1. Lattice energy is greater than hydration energy
2. Lattice energy is less than hydration energy
3. Lattice energy is equal to hydration energy
4. Dissolution is endothermic
During the evaporation of liquid
1. The temperature of the liquid will rise
2. The temperature of the liquid will fall
3. May rise or fall depending on the nature
4. The temperature remains unaffected
At higher altitudes the boiling point of water lowers because
1. Atmosphere pressure is low
2. Temperature is low
3. Atmosphere pressure is high
4. None of these
The boiling points of $C_{6} H_{6}$ , $C H_{3} O H$ , $C_{6} H_{5} N H_{2}$ , $C_{6} H_{5} N O_{2}$ are $80 ° C$ , $65 ° C$ , $184 ° C$ and $212 ° C$ respectively. Which of the following will have highest vapour pressure at room temperature ?
1. $C_{6} H_{6}$
2. Temperature is low
3. Atmosphere pressure is high
4. None of these
An ideal solution has two components A and B. If A is more volatile than B and also $P °_{A} > P_{T}$ then the correct relation between mole fraction of A in liquid (X) and vapour (Y) is
1. $X_{A} = Y_{A}$
2. $X_{A} > Y_{A}$
3. $X_{A} < Y_{A}$
4. Nothing can be said
A solution has 1 : 4 mole ratio of pentane to hexane. The vapour pressure of pure hydro-carbons at $20 ° C$ are 440 mmHg for pentane and 120 mmHg for Hexane. The mole fraction of pentane in vapour phase would be
1. 0.786
2. 0.549
3. 0478
4. 0.200
Consider a binary mixture of volatile liquids. If at $X_{A} = 0.4$ the vapour pressure of solution is 580 torr then the mixture could be
$(P °_{A} = 300 t o r r, P °_{B} = 800 t o r r)$
1. $C H C l_{3} - C H_{3} C O C H_{3}$
2. 0.549
3. 0478
4. 0.200
The lubricating action of an oil is more if it possess
1. high vapour pressure
2. low vapour pressure
3. high surface tension
4. high density
Which of the following plots does not represent the behaviour of an ideal binary liquid solution ?
1. plot of $p_{A}$ verses $x_{A}$ (mole fraction of A in liquid phase) is linear
2. plot of $p_{B}$ verses $x_{B}$ is linear
3. Plot of $p_{t o t a l}$ verses $x_{A}$ (or $x_{B}$ ) is linear
4. Plot of $p_{t o t a l}$ verses $x_{A}$ is non-linear
If liquids A and B form an ideal solution
1. The entropy of mixing is zero
2. The Gibbs free energy is zero
3. The Gibbs free energy as well as the entropy of mixing are each zero
4. The enthalpy of mixing is zero
Water and ethanol form non-ideal solution with positive deviation from Raoult's law. This solution will have vapour pressure
1. equal to vapour pressure of pure water
2. less than vapour pressure of pure water
3. more than vapour pressure of pure water
4. less than vapour pressure of pure ethanol
Mole fraction of toluene in the vapour which is in equilibrium with a solution containing benzene and toluene having 2 moles each is
Given : Saturation vapour pressure of benzene = 120 torr
Saturation vapour pressure of toluene = 80 torr
1. 0.5
2. 0.25
3. 0.6
4. 0.4
For an ideal binary liquid solution with $p °_{A} > p °_{B}, x_{A} a n d y_{A}$ represent the mole fraction of A in liquid phase and vapour phase respectively whereas $x_{B} a n d y_{B}$ represent the mole fraction of B in liquid phase and vapour phase respectively. Therefore, which of the following relation is correct ?
1. $x_{A} = y_{A}$
2. $x_{A} > y_{A}$
3. $\frac{x_{A}}{x_{B}} < \frac{y_{A}}{y_{B}}$
4. $\frac{x_{A}}{x_{B}} > \frac{y_{A}}{y_{B}}$
Total vapour pressure of mixture of 1 mol A $(p_{A} ° = 150 t o r r)$ and 2 mol B $(p_{B} ° = 240 t o r r)$ is 200 torr. In this case
1. there is positive deviation from Raoult's law
2. there is negative deviation from Raoult's law
3. there is no deviation from Raoult's law
4. molecular masses of A and B are also required for calculating the deviatio9n
A maxima or minima obtained in the temp;erature composition curve of a mixture of two liquid indicates
1. an azeotropic mixture
2. an eutectic formation
3. that the liquids are immiscible with one another
4. that the liquids are partially miscible at the maximum or minimum
A liquid is kept in a closed vessel. If a glass plate (negligible mass) with a small is kept on top of the liquid surface, then the vapour pressure of the liquid in vessel is
1. more tthan what would be if the glass plate removed
2. same as what would be if the glass plate were removed
3. less than what would be if the glass plate were removed
4. cannot be predicted
Given at 350 K $p °_{A}$ = 300 torr and $p °_{B}$ = 800 torr, the composition of the mixture having a normal boiling point of 350 K is
1. $x_{A}$ = 0.08
2. $x_{A}$ = 0.06
3. $x_{A}$ = 0.04
4. $x_{A}$ = 0.02
Which liquid pair shows a positive deviation fropm Raoult's law ?
1. Acetone - choloform
2. Benzene - methanol
3. Water - nitric acid
4. Water - hydrochloric acid
A mixture of ethyl alcohol and propyl alcohol has a vapour pressure of 290 mm at 300 K. The vapour presssure of propyl is 200 mm. If the mole fraction of ethyl alchohol is 0.6, its vapour pressure (in mm) at the same temperature will be
1. 350
2. 300
3. 700
4. 360
A binary liquid solution of n-heptane and ethyl alcohol is prepared. Which of the following statements correctly represents the behaviour of this liquid solution ?
1. The solution formed is an ideal solution.
2. The solution formed is a non-odeal solution with positive deviations from Raoult's law.
3. The solution formed is a non-odeal solution with negative deviations from Raoult's law.
4. Normal heptane exhibits positive deviations,m whereas ethyl alcohol exhibits negative deviations from Raoult's law.
Two liquids are mixed together to form a mixture which boils at same temperature and their boiling point is higher than the boiling point of either of them, so they shows.
1. no deviation from Raoult's law
2. positive deviation from Raoult's law
3. negative deviation from Raoult's law
4. positive or negative deviation from Raoult's law depending upon the composition
Benzene ( $C_{6} H_{6}$ , 78 g/mol) and toluene ( $C_{7} H_{8}$ , 92 g/mol) form an ideal solution. At $60 ° C$ the vapour pressure of pure benzene and pure toluene are 0.507 atm and 0.184 respectively. The mole fraction of benzene in a solution of these two chemicals that has a vpour pressure of 0.350 at $60 ° C$
1. 0.514
2. 0.690
3. 0.486
4. 0.190
At $25 ° C$ the vapour pressure of benzene $C_{6} H_{6}$ (78 g/mole) is 93.2w Torr and that of Toluene, $C_{7} H_{8}$ (92 g/mol), is 28.2 torr. A solution of 1.0 mole of $C_{6} H_{6}$ and 1.0 mol of $C_{7} H_{8}$ is prepare. Cauculate the mole fraction of $C_{6} H_{6}$ in the vapour above this solution (assume the solution is ideal).
1. 0.607
2. 0.768
3. 0.232
4. 0.393
Molal elevation constant of a liquid is
1. the evalution in b.p. which would be produced by dissolving one mole of solute in 100 g of solvent
2. the evalution in b.p. which would be produced by dissolving one mole of solute in 10 g of solvent
3. the evalution in b.p. which would be produced by dissolving one mole of solute in 1000 g of solvent
4. none of the above
The vapour pressure of pure liquid solvent is 0.50 atm. When a non-volatile solute B is aqdded to the solvent, its vapour pressure drops to m 0.30 atm. Thus, mole fraction of the compund B is
1. 0.6
2. 0.25
3. 0.45
4. 0.75
The vapour pressure of pure liquid is 10 torr and at the same temperature 1 g of B solid is dissolved in 20 g of A, its vapour pressure is reduced to 9.0 torr. If the molecular mass of A is 200 amu, then the molecular mass of B is
1. 100 amu
2. 90 amu
3. 75 amu
4. 120 amu
Vapour pressure of $C C l_{4} a t 25 ° C$ is 143 mmHg 0.05 g of a non-volatile solute (mol.wt = 65) is dissolved in 100 ml $C C l_{4}$ . Find the vapour pressure of the solution (Density of $C C l_{4}$ is $1.58 g / c m^{2}$ )
1. 143.99 mm
2. 94.39 mm
3. 199.34 mm
4. 14.197 mm
Among the following substances, the lowest vapour pressure is exerted by
1. Water
2. Mercury
3. Kerosene
4. Rectified spirit
The vapour pressure of pure liquid solvent A is 0.80 atm. When a non-volatile substance B is added to the solvent, its vapour pressure drops to 0.609 am. Mole fraction of the component B in the solution is
1. 0.50
2. 0.25
3. 0.75
4. -
  0.40
Two liquids X and Y form an ideal solution at 300 K, vapour pressure of the solution containing 1 mol of X and 3 mol of Y is 550 mmHHg. At the same temperature, if 1 mol of Y is further added to this solution, vapour pressure (in mmHg) of X and Y in their pure states will be respectively.
1. 200 and 300
2. 300 and 400
3. 400 and 600
4. 500 and 600.
An ideal solution has equal non-fractions of two volatil.e components A and B. In the vapour above the solution, the mole fractions of A and B
1. Are both 0.50
2. Are equal but necessarily 0.50
3. Are not very likely to be equal
4. Are 1.00 and 0.00 respectively
The vapour pressure of pure water at $75 ° C$ is 296 torr, the vapour pressure lowering due to 0.1 m solute is
1. 0.533 torr
2. 0.296 torr
3. 0.333 torr
4. 0.428 torr
Calculate the vapour pressure of a solution at $100 ° C$ containing 3 g of cane sugar in 33 g of water (At wt. C = 12, H = 1, O = 16)
1. 760 mm
2. 756.90 mm
3. 758.30 mm
4. None of these
Lowering of vapour pressure due to a solute in 1 molal aqueous solution at Calculate the vapour pressure of a solution at $100 ° C$ is
1. 13.44 mmHg
2. 14.12 mmHg
3. 31.2 mmHg
4. 35.2 mmHg
The vapour pressure of a dilute aqueous solution of glucose is 750 mmHg at 373 K. The mole fraction of the solute is
1. $\frac{1}{76}$
2. $\frac{1}{7.6}$
3. $\frac{1}{38}$
4. $\frac{1}{10}$
One mole of non-volatile solute is dissolved in two moles of water. The vapour pressure of the solution relative to that of water is
1. $\frac{2}{3}$
2. $\frac{1}{3}$
3. $\frac{1}{2}$
4. $\frac{3}{2}$
Dry air was passed successively through a solution of 5 g of a solute in a 180 g of water and then through pure water. The loss in weight of solution wa 2.50 g and that of pure solvent 0.04 g. The molecular weight of the solute is
1. 31.25
2. 3.125
3. 312.5
4. None of these
The vapour pressure of solvent is 20 torr, while that of its dilute solution is 17 torr, the mole-fraction of the solvent is
1. 0.6
2. 0.85
3. 0.5
4. 0.7
Relative decrease in vapour pressure of anaqueous solution containing 2 mol
$[C u {(N H_{3})}_{3} C l] C l i n 3 m o l H_{2} O i s \frac{1}{2}$ . When the given solution reaction with excess of $A g N O_{3}$ solution the number of moles of AgCl produced is
1. 1 mol AgCl
2. 0.25 mol AgCl
3. 2 mol AgCl
4. 0.40 mol AgCl
The degree of dissociation of $C a (N O_{3})_{2}$ in diulute aqueous solution containing 7.0 g of salt per 100.0 g of water at $100 ° C$ is 70%. If the vapour pressure of water at $100 ° C$ is 760 mmHg, the vapour pressure of the solution is
1. 748.2 mm Hg
2. 1492.6 mmHg
3. 373.2 mmHg
4. 74.03 mmHg
Normal boiling point $(T_{N})$ is defined as the tmperature when V.P. of liquid becomes equal to 1 atm and standard boiling point $(T_{S})$ is defined as the temperature when V.P. of liquid becomes equal to 1 bar. Which one is not correct if water is considered ?
1. $T_{N} = 100 ° C$
2. $T_{S} > 100 ° C$
3. $T_{S} < 100 ° C$
4. $T_{S} < T_{N}$
A solution containing 28 g of phosphorus and 315 g of $C S_{2}$ $(b . p . 46.3 ° C)$ boils at $47.98 ° C$ . If $K_{b}$ for $C S_{2}$ is $2.34 K k g m o l^{- 1}$ . The formula of phosphorus is (at mass of P = 31)
1. $P_{6}$
2. $P_{4}$
3. $P_{3}$
4. $P_{2}$
Elevation in boiling point of an aqueous solution of a non-electrolyte solute is $P_{4}$ . What is the depression in freezing point of this solution ?
$K_{b} (H_{2} O) = 0.52 ° m o l^{- 1} k g .$
$K_{f} (H_{2} O) = 1.86 ° m o l^{- 1} k g .$
1. $7.17 °$
2. $0.52 °$
3. $3.57 °$
4. $0.93 °$
Elevation in boiling point of a molar (1 M) glucose solution $(d = 1.2 g m o l^{- 1})$ is
1. $1.34 K_{b}$
2. $0.98 K_{b}$
3. $2.40 K_{b}$
4. $K_{b}$
0.15 g of a substance dissolved in 15 g of solvent boiled at a temperature by $0.216 ° C$ than that of the pure solvent. Calculate the molecular weight of the substance. Molal elevation constantt for the solvent is $2.16 ° C$
1. 216
2. 100
3. 178
4. None of these
A solution of 0.450 g of urea (mol. wt 60) in 22.5 g of water showed $0.170 ° C$ of elevation in boiling point. Calculate the molal elevation constanat of water.
1. $0.17 ° C$
2. $0.45 ° C$
3. $0.51 ° C$
4. $0.30 ° C$
At higher altitudes, water boils at temperature $< 100 ° C$ because
1. temperature of higher altitudes is low
2. atmospheric prressure is low
3. the proporation of heavy water increases
4. $0.30 ° C$
The elevation in boiling point of a solution of 13.44 g of $C u C l_{2}$ (molecular weight = 134.4, $K_{b} = 0.52 m o l a l i t y^{- 1}$ ) in 1 kg water using the following information will be
1. 0.16
2. 0.05
3. 0.1
4. 0.2
Which aqueous solution exhibits highest boiling point ?
1. 0.015 M glucose
2. $0.01 M K N O_{3}$
3. 0.015 M Urea
4. $0.01 M N a_{2} S O_{4}$
A solution containing 28 g phosphorous 315 g $C s_{2}$ . $(b . p . = 46.3 ° C)$ boils at $47.9 ° C$ . $(K_{b} f o r C s_{2} i s 2.34)$ What will be molecular formula of phosphorus ? (assuming complete association)
1. $P_{4}$
2. $P_{8}$
3. $P_{2}$
4. None
A solution of urea in waterhas boiling point of $100.15 ° C </math. Calculate the freezing point of the same if K_{f} a n d K_{b} for water are 1.87 k g m o l^{- 1} respectively.$
1. $- 0.54 ° C$
2. $- 0.44 ° C$
3. $- 0.64 ° C$
4. $- 0.34 ° C$
Calculate the normal boiling point of a sample of sea water found to contain 3.5% of NaCl and 0.13% of $M g C l_{2}$ by mass. The normal boiling point of water is $100 ° C a n d K_{b} w a t e r = 0.51 k g m o l^{- 1}$ . Assuming both the salts are completely ionised
1. $100.655 ° C$
2. $99.655 ° C$
3. $101.655 ° C$
4. $102.655 ° C$
An aqueous solution of glucose boils at $100.01 ° C$ . The molal elavation constant for water is $0.5 K m o l^{- 1} k g .$ . The number of molecules of glucose in the ssolution containing 100 g of water is
1. $6.23 \times 10^{23}$
2. $6.23 \times 10^{22}$
3. $12.046 \times 10^{20}$
4. $12.046 \times 10^{23}$
The latent heatof vaporisation of water is 9700 cal/mole and if theb.p. is $100 ° C$ , ebillioscopic constant of water is
1. $0.513 ° C$
2. $1.026 ° C$
3. $10.26 ° C$
4. $1.832 ° C$
If for a surcose solution elevation in boiling point is $0.1 ° C$ then what willbe the boiling point of NaCl solution for same molal concentration
1. $0.1 ° C$
2. $0.2 ° C$
3. $0.08 ° C$
4. $0.01 ° C$
The molal boiling point constant for water is $0.0513 ° C k g m o l^{- 1}$ . When 0.1 mole of sugar is dissolved in 200 ml of water, the solution boils under a pressure of one atmosphere at
1. $100.513 ° C$
2. $100.0513 ° C$
3. $100.256 ° C$
4. $101.025 ° C$
The boiling point of 0.1 m $K_{4} [F e {(C N)}_{6}]$ is expected to be $(K_{b} f o r w a t e r = 0.52 k g m o l^{- 1})$
1. $100.52 ° C$
2. $100.10 ° C$
3. $100.26 ° C$
4. $102.6 ° C$
The value of $K_{f}$ for water is $1.86 ° C$ , calculate from glucose solution. The value of $K_{f}$ for water caculated for NaCl solution will be
1. = 1.86
2. < 1.86
3. > 1.86
4. Zero
A solution of x moles of sucrose in 100 grams of water freezes at $- 0.2 ° C$ . As ince separates the freezing points goes down to $0.25 ° C$ . How many grams of ice would have separated?
1. 18 grams
2. 20 grams
3. 25 grams
4. 23 grams
The freezing point of a dilutte solution of acetamide in glacial acetic acid is 298 K. This is the value when crystals of
1. Acetgemide first appears
2. Acetic acid first appears
3. Both appear together
4. Ice first appears
In which case deprression freezing point is equal to cryoscopic constant for water
1. 6% by mass of urea in aqueous solution
2. 100 g of sucrose in 100 mL solution
3. 9 g of urea in 59 g aqueous solution
4. 1 M KCl solution
What freezing point depression would be predicted for 0.2 molal solution of benzoic acid in benzene if latent heat of fusion is $40.00 c a l g^{- 1}$ at 280 K (freezing point) for benzene ? (assume no change in molecular state)
1. $0.52 ° C$
2. $5.2 ° C$
3. $0.0052 ° C$
4. $0.78 ° C$
The amount of urea to be dissolved in 500 cc of water $(K_{f} = 1.86)$ to produce a depression of $0.186 ° C$ in the freezing point is
1. 9 g
2. 6 g
3. 3 g
4. 0.3 g
Freezing point of an aqueous solution is $- 0.186 ° C$ . Elevation of boiling point of the same solution is
$(i f K_{b} = 0.512 K m o l a l i t y^{- 1} a n d K_{f} = 1.86 K)$
1. $(i f K_{b} = 0.512 K m o l a l i t y^{- 1} a n d K_{f} = 1.86 K)$
2. $0.0512 ° C$
3. $0.0092 ° C$
4. $0.237 ° C$
Equimolar solutions of two non-electrolytes in the solvent have
1. same b.pt. but different f.pt.
2. same f.pt. but different b.pt.
3. same b.pt. and same f.pt.
4. different b.pt. and different f.pt.
Ethylene glycol is used as an anti-freeze in a cold climate. Mass of ethylene glycol which should be added to 4 kg of watger tp prevent it from freezing at $- 6 ° C$ will be
( $K_{f} f o r w a t e r = 1.86 K k g m o l^{- 1}$ and molar mass of ethylene glycol = $62 g m o l^{- 1}$ )
1. 800 g
2. 204.30 g
3. 400.00 g
4. 304.60 g
The freezing point of a solution containing $50 c m^{3}$ of ethylene glycol in 50 g of water is found to be $- 34 ° C$ .
Assuming ideal behaviour, calculate the density of ethylene glycol $(K_{f} f o r w a t e r = 1.86 K k g m o l^{- 1})$ .
1. $1.13 \frac{g}{c m^{3}}$
2. $2.00 \frac{g}{c m^{3}}$
3. $1.8 \frac{g}{c m^{3}}$
4. $2.25 \frac{g}{c m^{3}}$
Cryoscopic constant of a liquid
1. is the decrease in freezing point when 1 g of solute is dissolved per kg of the solvent
2. is the decrese in the freezing point when 1 mole of solute is dissolved per kg of the solvent
3. is the elevation for 1 molar solution
4. is a factor used for calculation of depression in freezing point.
Addition of 0.643 g of a Compound to 50 ml of benzene $(d e n s i t y = 0.879 g m o l^{- 1})$ lowers the freezing point from $50.51 ° C$ to $50.03 ° C$ . If $K_{f}$ for benzene is 5.12, the molecule of the compound is
1. 156.00
2. 312.00
3. 78.00
4. 468.000
What is the freezing point of a solution containing 8.1 g Br in 100 g water assuming the acid to be 90% ionised.
$(K_{f} f o r w a t e r = 1.8 K m o l e^{- 1})$
1. $0.85 ° C$
2. $- 3.53 ° C$
3. $0 ° C$
4. $- 0.35 ° C$
The freezing point of one molal NaCl solution assembing NaCl to be 100% dissociated in water is
(molal depression constant = 1.86)
1. $- 1.86 ° C$
2. $- 3.72 ° C$
3. $+ 1.8 ° C$
4. $+ 3.72 ° C$
Which of the following aqueous molal solution have highest freezing point
1. Urea
2. Barium chloride
3. Potassium bromide
4. Aluminium sulphate
When a solution containing w g of urea in 1 kg of water is cooled to $- 0.372 ° C$ , 200 g of ice is separated. If $K_{f} f o r w a t e r i s 1.86 K k g m o l^{- 1}$ , w is
1. 4.8 g
2. 12.0 g
3. 9.6 g
4. 6.0 g
3.24 g $H g {(N O_{3})}_{2}$ (Molecular mas 324) dissolved in 1000 g of water constitutes a solution having a freezing point $- 0.0558 ° C$ , while 21.68 g of $H g C l_{2}$ (Molecular mass 271) in 2000 g of water constitutes a solution with a freezing point of $- 0.0744 ° C$ . The $K_{f} f o r w a t e r i s 1.86 K k g m o l^{- 1}$ . About the state of ionisation of the two solids in water can be inferred that
1. $H g {(N O_{3})}_{2}$ is fully ionised but $H g C l_{2}$ is fully unionised.
2. $H g {(N O_{3})}_{2}$ and $H g C l_{2}$ both are completely ionised.
3. $H g {(N O_{3})}_{2}$ is fully unionised but $H g C l_{2}$ is fully ionised.
4. Both $H g {(N O_{3})}_{2}$ and $H g C l_{2}$ are completely ionised.
A living cell contains a solution which is isotonic with 0.3 (M) sugar solution. What osmotic pressure develops when the cell is placed in 0.1(M) KCl solution at body temperature ?
1. 5.08 atm
2. 2.54 atm
3. 4.92 atm
4. 2.46 atm
Osmotic pressure of 30% soplution of glucose is 1.20 atm and that of 3.42% solution of cane sugar is 2.5 atm. The osmotic pressure of the mixture containing equal volumes of the two solutions will be
1. 2.5 atm
2. 3.57 atm
3. 1.85 atm
4. 1.3 atm
If "A' contains 2% NaCl and is separated by a semi-ermeable membrane from 'B' which contains 10% NaCl, which event will occur ?
1. NaCl will flow from 'A' to 'B'
2. NaCl will flow from 'B' to 'A'
3. Water will flow from 'A' to 'B'
4. Water will flow from 'B' to 'A'
Which has maximum osmotic pressure at temperature T K ?
1. 150 mL of 1.0 M urea solution
2. 210 mL of 1.0 M glucose solution
3. Mixture oif 150 mL of 1.0 M urea solution and 210 mL of 1.0 M glucose solution
4. All of the above are isotonic solutions.
What is osmolarity of a 0.20 M KCl solution ?
1. 0.10 osmol
2. 0.20 osmol
3. 0.30 osmol
4. 0.40 osmol
A 5% solution of cane sugar (molar mass = 342) is isotonic with 1% of a solution of an known solute. The molar mass of known slute in g/mol is
1. 136.2
2. 171.2
3. 68.4
4. 34.2
Two solutions of $K N O_{3} a n d C H_{3} C O O H$ are prepared separately. Molarity of both is 0.1 M and osmotic pressures $P_{1} a n d P_{2}$ respectively. The correct relationship between the osmotic pressures is
1. $P_{2} > P_{1}$
2. 171.2
3. 68.4
4. 34.2
The wt of urea of getting fresh water from sea water is known as
1. Osmosis
2. Filtration
3. Desaltation
4. Reverse Osmosis
In the phenomenon of osmosis, the membrane allow passage of
1. Solute only
2. Solvent only
3. Both solute andd solvent
4. None of these
A 5.8% (wt. / vol.) NaCl solution will exert an osmotic pressure closest to which one of the following.
1. 5.8% (wt. / vol.) sucrose solution
2. 5.8% (wt. / vol.) glucose solution
3. 2 molal sucrose solution
4. 1 molal glucose solution
Sea water is 3.5% by mass of a salt and has a density $1.04 g c m^{- 3}$ at 293 K. Assuming the salt to be sodium chlroide, calculate the osmotic pressure of sea water. Assume complete ionisation of the salt
1. 26.93 atm
2. 29.93 atm
3. 28.93 atm
4. 27.93 atm
Osmotic pressure of blood is 7.65 atm at 310 K. An aqueous solution of glucose that will be isotonic with blood is -------------- wt./vol.
1. 5.41 %
2. 3.54 %
3. 4.53 %
4. 53.4 %
A solution containing 8.6 g urea in one litre was found to be isotonic with a 5% (wt./vol.) swolution of an organic non-volatile solute. The molecular weight of latter is
1. 348.9
2. 34.89
3. 3489
4. 861.2
The wt. of urea dissoved in 100 ml solution which produce an osmotic pressure of 20.4 atm, will be
1. 5 g
2. 4 g
3. 3 g.
4. 6 g
The relationship between Osmotic pressure at 273 K when 10 g of glucose $(P_{1})$ , 10 g urea $(P_{2})$ and 10 g sucrose $(P_{3})$ are dissolved in 250 ml of water is
1. $P_{1} > P_{2} > P_{3}$
2. $P_{3} > P_{1} > P_{2}$
3. $P_{2} > P_{1} > P_{3}$
4. $P_{2} > P_{3} > P_{1}$
Osmotic pressure of a urea solution at $10 ° C$ is 500 mm. Osmotic pressure of the solution become 105.3 mm. When it is diluted and temperature raised at $25 ° C$ . The extent of dilution is
1. 6 times
2. 5 times
3. 7 times
4. 4 times
A 2% solution of cane sugar is isotonic 0.5% x solution. The molecular weight of the substance 'x' is
(Assume that x does not undergo association or dissociation)
1. 34.2
2. 85.5
3. 95.58
4. 126.98
The van't Hoff factor i for a compound which undergoes dissociation in one solvent and association in other solvent is resxpectively
1. greater than one and greater than one
2. less than one and greater than one
3. less than one and les than one
4. greater than one and less than one
Osmolarity of 0.02 M potassium ferrocyanide solution at 300 K is
(assume solute is 100% ionized)
1. 0.10 osmol
2. 0.20 osmol
3. 0.02 osmol
4. 0.004 osmol
$π_{1}, π_{2}, π_{3} and π_{4}$ are the osmotic pressure of 5% $(\frac{W}{V})$ solutions of urea, fructose, sucrose and KCl respectively at certain temperate. The correct order of magnitude is
1. $π_{1} > π_{4} > π_{2} > π_{3}$
2. $π_{1} < π_{4} < π_{2} < π_{3}$
3. $π_{4} > π_{1} > π_{2} > π_{3}$
4. $π_{4} > π_{1} > π_{3} > π_{2}$
Moles of $K_{2} {SO}_{4}$ to be dissolved in 12 mol water to lower its vapour pressure by 10 mmHg at a temperature at which vapour pressure of pure water is 50 mm is
1. 3 mol
2. 2 mol
3. 1 mol
4. 0.5 mol
If for a sucrose solutioin elevation in boing point is $0.1 ° C$ then what will be the boiling point of NaCl solution for same molal concentration
1. $0.1 ° C$
2. $0.08 ° C$
3. $0.1 ° C$
4. $0.08 ° C$
For 0.1 M solution, the colligative property will follow the order
1. $N a C l > N a_{2} S O_{4} > N a_{3} P O_{4}$
2. $N a C l > N a_{2} S O_{4} \approx N a_{3} P O_{4}$
3. $N a C l < N a_{2} S O_{4} < N a_{3} P O_{4}$
4. $N a C l < N a_{2} S O_{4} = N a_{3} P O_{4}$
If $α$ is the degree of dissociation of $N a_{2} S O_{4}$ , the van's Hoff factor (i) used for calculating the molecular mass is
1. $1 + α$
2. $1 + 2 α$
3. $1 - α$
4. $1 - 2 α$
pH of a 0.1 M monobasic acid is found to be 2. Hence it osmotic pressure at a given temp T K is -
1. 0.1 RT
2. 0.11 RT
3. 1.1 RT
4. 0.01 RT
The van't Hoff factor i for an infinitely dilute solution of $N a H S O_{4}$ is
1. $\frac{1}{2}$
2. $\frac{1}{3}$
3. 3
4. 2
Aluminium phosphate is 100% ionised in 0.01 molal aqueous solution. Hence, $\frac{Δ T_{b}}{K_{b}}$ is
1. 0.01
2. 0.015
3. 0.0175
4. 0.02
1.0 molal aqueous solution of an electtrolyte $X_{3} Y_{2}$ is 25% ionized. The boiling point of the solution is
$(K_{b} f o r H_{2} O = 0.52 K k g / m o l)$
1. 375.5 K
2. 374.04 K
3. 377.12 K
4. 373.25 K
A solution of crab haemocyanin, a pigmented protein extracted from crabs was prepared by dissolving 0.750 g in $125 c m^{3}$ of an aqueous medium. At $4 ° C$ as osmotic pressure rise of 2.6 mm of the solution was observed. The solution has a density of $1.00 \frac{g}{c m^{3}}$ . Determine the molecular weight of the protein.
1. $53.14 \times 10^{5} \frac{g}{m o l}$
2. $52.14 \times 10^{5} \frac{g}{m o l}$
3. $51.14 \times 10^{5} \frac{g}{m o l}$
4. $54.14 \times 10^{5} \frac{g}{m o l}$
The freezing point of 0.05 m solutions of a non-electrolyte in water is
1. $- 1.86 ° C$
2. $- 0.93 ° C$
3. $- 0.093 ° C$
4. $0.93 ° C$
Which aqueous solution would possess the lowest boiling pointg ?
1. 1% NaCl solution
2. 1% Urea solution
3. 1% Glucose solution
4. 1% Sucrose solution
An aqueous solution boils at $100.50 ° C$ . The freezing point of the solution would be $(K_{b} f o r w a t e r = 0.51 ° C / m), (K_{f} f o r w a t e r = 1.86 ° C / m)$ . [No association or dissociation]
1. $0 ° C$
2. $- 1.86 ° C$
3. $- 1.82 ° C$
4. $+ 1.82 ° C$
20 g of a binary electrolyte (mol. wt. = 100) are dissolved in 500 g of water. The freezing point of the solution will be $- 0.74 ° C K_{f} = 1.86 K m o l a l i t y^{- 1} .$ The degree of ionikzation of the electrolyte is
1. 50%
2. 75%
3. 10%
4. 0%
The ratio of the value of any colligative property for $K_{4} [F e {(C N)}_{6}]$ solution to that of $F e_{4} {[F e {(C N)}_{6}]}_{3}$ (prussian blue), solution is nearly
1. 1
2. 0.71
3. 1.4
4. Less than 1
ASSERTION : The boiling and melting points of amides is not the correct explanation of the assertion.
REASON : It is due to strong inter-molecular hydrogen bonding in their molecules.
1. If both assertion and reason are true and the reason is the correct explanation of the assertion.
2. If both assertion and reason are true but reason is not the correct explanation of the assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : Molar heat of vaporisation of water is greater than benzene.
REASON : Molar heat of vaporisation is the amount of heat required to vaporise one mole of liqujid at constant temperature.
1. If both assertion and reason are true and the reason is the correct explanation of the assertion.
2. If both assertion and reason are true but reason is not the correct explanation of the assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : Molecular mass of benzoic acid when determined by colligative properties is found high.
REASON : Dimerisation of benzoic acid.
1. If both assertion and reason are true and the reason is the correct explanation of the assertion.
2. If both assertion and reason are true but reason is not the correct explanation of the assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : Use of pressure cooker reduces cooking time.
REASON : At higher pressure cooking occurs faster.
1. If both assertion and reason are true and the reason is the correct explanation of the assertion.
2. If both assertion and reason are true but reason is not the correct explanation of the assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : $C C l_{4}$ and $H_{2} O$ are immiscible.
REASON : $C C l_{4}$ is a polar solvent.
1. If both assertion and reason are true and the reason is the correct explanation of the assertion.
2. If both assertion and reason are true but reason is not the correct explanation of the assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : Isotonic solution do not show the phenomenon of osmosis.
REASON : Isotonic solutions have equal osmotic prressure.
1. If both assertion and reason are true and the reason is the correct explanation of the assertion.
2. If both assertion and reason are true but reason is not the correct explanation of the assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : Boiling point of water is $100 ° C$ although water boils below $100 ° C$ on mountains.
REASON : Boiling point of a liquid is the temperature at which V.P. of liquid becomes equal to 1 atm.
1. If both assertion and reason are true and the reason is the correct explanation of the assertion.
2. If both assertion and reason are true but reason is not the correct explanation of the assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : Ebulliscopy or cryoscopy cannot be used for the determination of molar mass of polymers.
REASON : High molar mass solute leads to very low value of $∆ T_{b} o r ∆ T_{f}$ .
1. If both assertion and reason are true and the reason is the correct explanation of the assertion.
2. If both assertion and reason are true but reason is not the correct explanation of the assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : For isotonic solution $C_{1} = C_{2}$
REASON : For isotonic solution $π_{1} = π_{2}$ .
1. If both assertion and reason are true and the reason is the correct explanation of the assertion.
2. If both assertion and reason are true but reason is not the correct explanation of the assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : Osmotic pressure of non-aqueous solution can be determined by Berkeley-Hartley method.
REASON : The semi-permeable membrane used in Berkeley-Harley method is ${Cu}_{2} [Fe {(CN)}_{6}]$
1. If both assertion and reason are true and the reason is the correct explanation of the assertion.
2. If both assertion and reason are true but reason is not the correct explanation of the assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : Addition of solvent to a solution always lowers the V.P.
REASON : The increase in relative surface area given rise to an increase in V.P. for a given solution.
1. If both assertion and reason are true and the reason is the correct explanation of the assertion.
2. If both assertion and reason are true but reason is not the correct explanation of the assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : A cook crises more in cutting onion rather than cutting an onion taken out from refrigerator.
REASON : The cold onion has lower vapour pressure of its volatile content.
1. If both assertion and reason are true and the reason is the correct explanation of the assertion.
2. If both assertion and reason are true but reason is not the correct explanation of the assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : A mixture of cyclohexane and ethanol shows negative deviation from Raoult's Law
REASON : Cyclohexane reduces the inter-molecular attraction between ethanol molecules.
1. If both assertion and reason are true and the reason is the correct explanation of the assertion.
2. If both assertion and reason are true but reason is not the correct explanation of the assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : 0.1 m solution of glucose has same increase in the freezing point as 0.1 m soluttion of urea if both are aqueous solution.
REASON : $K_{f}$ for both same value.
1. If both assertion and reason are true and the reason is the correct explanation of the assertion.
2. If both assertion and reason are true but reason is not the correct explanation of the assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : If red blood cells were removed from the body and placed in pure water, pressure inside the cells increases.
REASON : The concentration of salt content in the cell increases.
1. If both assertion and reason are true and the reason is the correct explanation of the assertion.
2. If both assertion and reason are true but reason is not the correct explanation of the assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
On adding solute to a solvent having vapour pressure 0.80 atm, vapour pressure reduces to 0.60 atm. Mole fraction of solute is
1. 0.25
2. 0.75
3. 0.50
4. 0.33
A solution containing 330 g of non-volatile solute in exactly 90 gm water has a vapour pressure of 21.85 mmHg at $25 ° C$ . Further 18 g of water is then added to the solution. The resulting solution has a vapour pressure of 22.15 mmHg at $25 ° C$ . Calculate the molecular weight of the solute
1. 74.2
2. 75.6
3. 67.83
4. 78.7
Vapour pressure of a solution of 5 g of non-electrolyte in 100 g of water at a particular temperature is $2985 N / m^{2} .$ The vapour pressure of pure water is $3000 N / m^{2} .$ The molecular weight of the solute is
1. 60
2. 120
3. 180
4. 380
Azeotropic mixture of HCl and water has
1. 84% HCl
2. 22.2% HCl
3. 63% HCl
4. 20.2% HCl
The osmotic pressure at $17 ° C$ of an aqueous solution containing 1.75 g of sucrose per 150 ml solution is
1. 0.8 atm
2. 0.08 atm
3. 8.1 atm
4. 9.1 atm
A 1.2 of solution of NaCl is isotonic with 7.2 of solution of glucose. Calculate the van't Hoff factor of NaCl solution
1. 2.36
2. 1.50
3. 1.95
4. 1.00
0.6 g of a solute is dissolved in 0.1 litre of a solvent which develops an osmotic pressure of 1.23 atm at $27 ° C$ . The molecular mass of the substance is
1. $149.5 g m o l^{- 1}$
2. $120 g m o l^{- 1}$
3. $430 g m o l^{- 1}$
4. None of these
The boiling point of a solution of 0.1050 g of a substance in 15.84 g of ether was found to be $100 ° C$ higher than that of pure ether. What is the molecular weight of the substance ? [Molecular elevation constant of ether per 100 g = 21.6]
1. 144.50
2. 143.18
3. 140.28
4. 146.66
Boiling point of chloroform was raised by 0.323 K, when 0.5143 g of anthracene was dissolved in 35 g of chloroform. Molecular mas of anthracene is
$(K_{b} f o r C H C l_{3} = 3.9 K k g m o l^{- 1})$
1. 79.42 g / mol
2. 132.32 g / mol
3. 177.42 g / mol
4. 242.32 g / mol
The boiling point of water $(100 ° C)$ becomes $100.52 ° C$ , if 3 grams of a non-volatile solute is dissolved in 200 ml of water. The molecular weight of solute is
$(K_{b} f o r w a t e r i s 0.6 K k g m o l^{- 1})$
1. $12.2 g m o l^{- 1}$
2. 15.4 g mol
3. $17.3 g m o l^{- 1}$
4. 20.4 g mol
Normal boiling point of water is 373 K (at 760 mm). Vapour pressure of water at 298 K is 23 mm. If the enthalpy of evaporation is 40.656 kJ/mole, the boiling point of water at 23 mm pressure will be
1. 250 K
2. 294 K
3. 51.6 K
4. 12.5 K
A 0.2 molal aqueous solution of a weak acid (HX) is 20% ionized. The freezing point of this solution is
(Given $K_{f} = 1.86 ° C$ for water)
1. $- 0.31 ° C$
2. $- 0.45 ° C$
3. $- 0.53 ° C$
4. $- 0.90 ° C$
A 0.001 molal solution of $[P t {(N H_{3})}_{4} C l_{4}]$ in water had a freezing point depression of $0.0054 ° C$ . If $K_{f}$ for water is 1.80, the correct formulation for the above molecule is
1. $[P t {(N H_{3})}_{4} C l_{3}] C l$
2. $[P t {(N H_{3})}_{4} C l] C l_{2}$
3. $[P t {(N H_{3})}_{4} C l_{2}] C l_{3}$
4. $[P t {(N H_{3})}_{4} C l_{4}]$
An aqueous solution of a weak monobasis acid containing 0.1 g in 21.7 g of water frfeezes at 272.813 K. If the value of $K_{f}$ for water is 1.86 K/m, What is the molecular mass of the monobasic acid ?
1. 50 g / mol
2. 46 g / mol
3. 55 g / mol
4. 60 g / mol
$K_{f}$ of 1,4 dioxane is $4.9 m o l^{- 1}$ for 1000 g. The depression in freezing point for a 0.001 m solution in dioxane is
1. 0.0049
2. 4.9 + 0.001
3. 4.9
4. 0.49
How many litres of $C O_{2}$ at STP will be formed when 100 ml of $0.1 M H_{2} S O_{4}$ reacts with excess of $N a_{2} S O_{3}$ ?
1. 22.4
2. 2.24
3. 0.224
4. 5.6
A solution is obtained by dissolving 12 g of urea (mol.wt. of 60) in a litre of water. Another solution is obtained by dissolving 68.4 g of cane sugar (mol. wt. 342) in a litre of water at are the same temperature. The lowering of vapour pressure in the first solution is
1. same as that of 2nd solution
2. nearly one-fifth of 2nd solution
3. Double that of 2nd solution
4. Nearly five times that of 2nd solution
The vapour pressures of ethanol and methanol are 42.0 mm and 88.5 mmHg respectively. An ideal solution is formed at the same temperature by mixing 46.0 g of ethanol with 16.0 g of methanol. The mole fraction of methanol in the vapour is
1. 0.467
2. 0.502
3. 0.513
4. 0.556
Which of the following plots represents the behaviour of an ideal binary liquid solution ?
1. Plot of $P_{t o t a l} V S Y_{A}$ (mol-fraction of A in vapour phase) is linear
2. Plot of $P_{t o t a l} V S Y_{B}$ is linear
3. Plot of $1 / P_{t o t a l} V S Y_{A}$ is linear
4. Plot of $1 / P_{t o t a l} V S Y_{B}$ is non-linear.
For a binary ideal liquid solution, the total pressure of the solution is given as
1. $P_{t o t a l} = P *_{A} (P *_{A} - P *_{B}) X_{A}$
2. $P_{t o t a l} = P *_{B} (P *_{A} - P *_{B}) X_{A}$
3. $P_{t o t a l} = P *_{A} (P *_{B} - P *_{A}) X_{A}$
4. $P_{t o t a l} = P *_{B} (P *_{B} - P *_{A}) X_{A}$
The relationshop between the values of osmotic pressures of 0.1 M solutions of $K N O_{3} (P_{1}) a n d C H_{3} C O O H (P_{2})$ is
1. $P_{1} > P_{2}$
2. $P_{2} > P_{1}$
3. $P_{1} = P_{2}$
4. $\frac{P_{1}}{(P_{1} + P_{2})} = \frac{P_{2}}{(P_{1} + P_{2})}$
The vapour pressure of solvent is 20 torr, while that of its dilute solution is 17 torr, the mole fraction of the solvent is
1. 0.6
2. 0.4
3. 0.5
4. 0.7
NaCl is added to 1 litre water to such an extent that $∆ T / K_{f}$ becomes to $\frac{1}{500}$ , the wt. of NaCl added is
1. 5.85 g
2. 0.585 g
3. 0.0585 g
4. None of these
If the total vapour pressure of the liquid mixture A and B is given by the equation. $P = 180 X_{A} + 90$ then the ratio of the vapour pressure of the pure liquids A and B is given by
1. 3 : 2
2. 4 : 1
3. 3 : 1
4. 6 : 2
The vapour pressures of ethanol and methanol are 44.54 mmHg and 88.7 mmHg respectively at the same temperature. An ideal solution is formed by mixing 60 g of ethanol and 40 g of methanol. The mole fraction of methanol in the vapour phase is
1. 0.66
2. 0.55
3. 0.11
4. 0.33
The molality of a urea solution in which 0.0200 g of urea $(N H_{2} C O N H_{2})$ is added to $0.400 d m_{3}$ of water at STP is
1. 0.555 molal
2. $5.55 \times 10^{- 4} m o l a l$
3. $8.33 \times 10^{- 2} m o l a l$
4. 33.3 molal
The vapour pressure of benzene at $80 ° C$ is lowered by 10 mm by dissolving 2 g of a non-volatile substance in 7y8 g of benzene. The vapour pressure of pure benzene at $80 ° C$ is 750 mm. The molecular weight of the substance will be
1. 15
2. 150
3. 1500
4. 148
ASSERTION : Azeotropic mixtures are formed only by non-ideal solutions and they may have boiling points either greater than both the components or less than both the components.
REASON : The composition of the vapour phase is same as that of the liquid phase of an azeotropic mixture.
1. If both assertion and reason are true and reason is the correct explanation of the assertion.
2. If both assertion and reason are true and reason is not the correct explanation of the assertion.
3. If assertion is true but reason is false.
4. If assertion and reason both are false.
ASSERTION : Molar heat of vaporisation of water is greater than benzene.
REASON : Molar heat of vaporisation is the amount of heat required to vaporise one mole of liquid at constant temperature.
1. If both assertion and reason are true and reason is the correct explanation of the assertion.
2. If both assertion and reason are true and reason is not the correct explanation of the assertion.
3. If assertion is true but reason is false.
4. If assertion and reason both are false.
ASSERTION : Isotonic solution do not show the phenomenon of osmosis.
REASON : Isotonic solution have equal osmotic pressure.
1. If both assertion and reason are true and reason is the correct explanation of the assertion.
2. If both assertion and reason are true and reason is not the correct explanation of the assertion.
3. If assertion is true but reason is false.
4. If assertion and reason both are false.