Surface Chemistry

If x is the amount of adsorbate and m is the amount if adsorbent , which of the following relations is not related to adsorption process ?
1. $\frac{x}{m} = p x T$
2. $\frac{x}{m} = f (p) a t c o n s \tan t T$
3. $\frac{x}{m} = f (T) a t c o n s \tan t p$
4. $p = f (T) a t c o n s \tan t \frac{x}{m}$
When temperature is raised , the viscosity of liqid decreses , this ia because
1. Decreased volume of the solution
2. Increase in temperature increases the average kinetic energy of molecules , which overcome the attractive foece between them
3. Decreased covalent and hydrogen bond forces
4. Increased attraction between molecules
Which one of the following is an incorrect statement for physisorption ?
1. It is reversible process
2. It requires less heat of adsorption
3. It requires activation energy
4. It takes place at low temperature
Which is correct in case of vander Waals adsorption ?
1. High temperature , low pressure
2. Low temperature , high pressure
3. Low temperature , low pressure
4. High temperature, high pressure
According to Langmuir adsorption isotherm, the amount of gas adsorbedd at very high pressures
1. Reaches a constant limiting value
2. Goes on increasing with pressure
3. goes on decreasing with pressure
4. Increases first and decreases later with pressure
Noble gas are adsorbed by
1. Anhydrous calcium chloride
2. Ferric hydroxide
3. Conc. $H_{2} S O_{4}$
4. Activated coconut charcoal
The adsorption of a gas on a solid surface varies with pressure if the gas in which of the following manner
1. Fast->Slow -> Independant of the pressure
2. Slow->Fasr-> Independant of the pressure
3. Independant of the pressure ->Fast->Slow
4. Independant of the pressure ->Slow->Fast
Softening of hard water is done using sodium aluminium silicate (zeolte). The causes :
1. adsorption of $C a^{2 +} a n d M g^{2 +}$ ions of hard water replacing $N a^{+}$ ions
2. adsorption of $C a^{2 +} a n d M g^{2 +}$ ions of hard water replacing $A l^{3 +}$
3. adsorption of $C a^{2 +} a n d M g^{2 +}$ ions of hard water replacing $C u^{3 +}$
4. None of these
50ml of 1M oxalic acid is shaken with 0.5g of wood charcoal. The final concentration of the sodium after adsorption is 0.5M .Amount of oxalic acid absorbed per gm of charcoal is
1. 3.45g
2. 3.15g
3. 6.30g
4. None of these
Langmuir adsorption isotherm is best suitable for
1. Chemisorption
2. Physisorption
3. Both Chemisorption and Physisorption
4. None of these
Which are not purely surface phenomena ?
1. Adsorption,Viscosity
2. Adsorption,absorption
3. Viscosity,surface tension
4. Adsorption,viscosity
Animal charcoal is used in decolourising colour liquids because it is a good
1. Adsorbate
2. Adsorbent
3. Oxidising agent
4. Reducing agent
Bone charcoal is used to decolorise sugar.In this case bone and colour on sugar respectively are
1. Adsorbate, Adsorbent
2. Both are adsorbent
3. Both are adsorbate
4. Adsorbent, Adsorbate
What will be the effect of increase in tempertaure on physical adsorption?
1. It will decrease
2. It will increase
3. First increase then decrease
4. None of these
Which of the following statements about chemisorption is not applicable?
1. It invloves chemical forces between adsorbent and adsorbate
2. It is irreversible in nature
3. It invloves high heat of adsorption
4. It does not require activation energy
Which one is not the characteristic of chemisorption :
1. Multilayer adsorption
2. Exothermic nature
3. Stron adsorption by adsorption sites
4. Irreversible
Gas masks containing activated charcoal to remove poisonous gases from atmosphere acts on principle of
1. Adsorption
2. Absorption
3. Sorption
4. All of these
0.2g of fine animal charcoal is mixed with half litre of acetic acid solution and shaken for 30minutes
1. Concentration remains same
2. Concentration increases
3. Concentration of the solution decarese
4. None of these
The equation for Freundlich adsorption isotherm is
1. $\frac{x}{m} = k p^{\frac{1}{n}}$
2. $x = m k p^{\frac{1}{n}}$
3. $\frac{x}{m} = k p^{- n}$
4. None of these
Adsorption due to strong chemical forces is called
1. Chemisorption
2. Physiosorption
3. Reverse adsorption
4. Both Physiosorption and Reverse adsorption
Catalysts are more effective in
1. Finely powdered state
2. Colloidal state
3. Rough surface
4. All of these
Activated charcoal is used to remove colouring matter from pure subsatnces . It works by
1. Oxidation
2. Reduction
3. Bleaching
4. Adsorption
Adsorption is the phenomenon in which a substance :
1. Accumulates on the surface of the other substance
2. goes into the body of the other substances
3. remains close to the other surface
4. none of these
Which is not a purely surface phenomena ?
1. surface tension
2. adosrption
3. absorption
4. none of these
Physical adsorption is accompanied by
1. Decrease in entropy of system
2. Decrease in enthalpy
3. The value of $T ∆ S$ is negative
4. All of these
For adsorption of gas on solid surface, the plots of log $\frac{x}{m}$ versus log P is linear with a slope equal to
1. K
2. logK
3. logC
4. $\frac{1}{n} (n b e i n g i n t e g e r)$
Which forms multimolecular layer during adsorption?
1. Physical adsorption
2. Chemisorption
3. Both physical adsorption and chemisorption
4. None of these
In a process,adsorption and absorption take place together .This term is defined by
1. desorption
2. adsorption
3. sorption
4. absorption
If $H_{2}$ gas is made to adsorb on a surface , then the fraction of surface area of adsorbent covered by gas molecules is proportional to
1. p
2. $p^{0}$
3. $p^{\frac{1}{2}}$
4. $p^{2}$
Graph between log $\frac{x}{m}$ and log p is a straightt line inclined at an angle of $45^{0}$ .When pressure 0.5 atm and ln k=0.693, the amount of solute adorbed per gram of adsorbent will be
1. 1
2. 1.5
3. 0.25
4. 2.5
Milk is a colloid in which
1. A liquid s dispersed in liquid
2. A solid is dispersed in liquid
3. A gas is dispersed in liquid
4. Some sugar is dispersed in water
If the dispersed phase is a liquid and the dispersion medium is a solid , the colloid is known as a/an
1. sol
2. emulsion
3. gel
4. foam
Colloidal sols can be purified by
1. dialysis
2. ultrafiltration
3. ultracentrifugation
4. all of these
The stability of lyophilic colloids is due to
1. Charge on their particles
2. A layer of dispersion medium on theier particles
3. The smaller size of their particles
4. The large size of their particles
Some of the properties given below are for colloidal sols
(i) Viscosity is same as that of the medium
(ii) Extensive hydration takes place
(iii) Migration of the particles under electronic field
(iv) Particles cannot be detected even under ultra microscope

Properties applicable for lyophilic and lyophobic colloidal sols are
1. Lyophilic (i) and (ii)
  Lyophobic (iii) and (iv)
2. Lyophilic (i) and (iii)
  Lyophobic (ii) and (iv)
3. Lyophilic (ii) and (iv)
  Lyophobic (i) and (iii)
4. Lyophilic (ii) and (iii)
  Lyophobic (i) and (iv)
Gelatin is mostly used in making ice cream in order to
1. Prevent makin of colloid
2. To stabilise the colloid abd prevent crystalisation
3. To stabilise the mixture
4. To enrich the aroma
The stability of the dispersed phase in a lyophilic colloids is due to
1. High viscosity of the medium
2. The formation of electrical layer between two phases
3. High surface tension of sol
4. None of these
Which one of the following is not a colloidal sollution?
1. Smoke
2. Ink
3. Air
4. Blood
The process of seperation of colloids by passing through semi permeable membrane is called
1. Filtration
2. Electrophoresis
3. Dialysis
4. Ultrafiltration
A liquid aerosol is colloidal system of
1. A liquid dispersed in a solid
2. A liquid dispersed in a gas
3. A gas dispersed in a liquid
4. A solid dispersed in a gas
The stabilization of a dispersed phase in a lyophobic colloidal sol is due to
1. the adsorption of charged substances on dispersed phase
2. the large electrokinetic potential developed in the colloid
3. the viscosity of the medium
4. the formation of an electrical layer between two phases
Size of colloidal particls varies from
1. $10^{- 7} t o 10^{- 9} m$
2. the large electrokinetic potential developed in the colloid
3. the viscosity of the medium
4. the formation of an electrical layer between two phases
The stabilisation of a lyophobic colloid is due to
1. preferential adsorption of similar charged particle on colloids surface
2. the large electrokinetic potential developed in the colloid
3. the viscosity of the medium
4. the formation of an electrical layer between two phases
Tyndall effect is shown by
1. Colloidal solution
2. Osmotic solution
3. Isotonic solution
4. Hypertonic solution
Which one is an example of multimolecular colloid system?
1. Soap dispersed in water
2. Protein dispersed in water
3. Gold dispersed in water
4. Gum dispersed in water
The number of phases in colloidal system are
1. One
2. Two
3. Three
4. Four
Surface tension of lyophilic sols is
1. Lower than that of $H_{2} O$
2. More than that of $H_{2} O$
3. Equal to that of $H_{2} O$
4. None of these
Smoke is a dispersion of
1. gas in gas
2. gas in solid
3. solid in gas
4. liquid in gas
The colloidal sols are purified by
1. Peptisation
2. Coagulation
3. Dialysis
4. Flocculation
Bredig's arc method cannot be used to prepare colloidal solution of which of the following
1. Pt
2. Fe
3. Ag
4. Au
The stability of hydrophobic sol is due to
1. Solvatiion of colloidal particles
2. The charge on the colloidal particles
3. The size of particles
4. None of these
The volume of colloidal particle , $V_{C}$ as compared to the volume of a solute particle in a true solution $V_{S}$ could be
1. $\frac{V_{C}}{V_{S}} = 1$
2. $\frac{V_{C}}{V_{S}} = 10^{23}$
3. $\frac{V_{C}}{V_{S}} = 10^{- 3}$
4. $\frac{V_{C}}{V_{S}} = 10^{3}$
Lyophilic sols are more stable than lyophobic sols because
1. The colloidal particles have postive charge
2. The colloidal particles have negative charge
3. The colloidal particles are solvated
4. There are strong electrostatic repulsion between negatively charged colloidal particles
Lyophilic sols are more stable than lyophobic sols because their particles are
1. Postively charged
2. Negatively charged
3. All soluble
4. Attract each other
Which one of the following statement is false for hydrophilic sols ?
1. they do not require electrolyte for stability
2. their viscosity is of the order of that of water
3. their surface tension is usually lower than that of dispersion medium
4. none of these
A dispersion of AgCl in water is
1. Hydrophilic colloid
2. An emulsion
3. An alcosol
4. Hydrophobic sol
Oils and fats are obtained by saponification of potassium stearate.Its formula is $C H_{3} - (C H_{2})_{16} - C O O^{-} K^{+}$ Lyophobic end of atom is $(C H_{3})$ and lyophilic end is $C O O^{-} K^{+}$ potassium stearate is example of
1. Lyophobic colloids
2. Lyophilic colloids
3. Combined colloids or micelles
4. Macromolecular colloids
Which of the following is contribulted towrds the extra stability of lyophilic colloids ?
1. Hydration
2. Charge
3. Colour
4. Tyndall effect
$A s_{2} S_{3}$ sol is a
1. Positive colloid
2. Negative colloid
3. Neutral colloid
4. None of these
Which of the following statements is not correct for a lyophobic solution?
1. It can be easily solvated
2. It carries charges
3. The coagulation of this sol is irreversible in nature
4. It is less stable in a solvent
Purification of colloids is done by the process of
1. Electrophoresis
2. Electrodispersion
3. Peptization
4. Ultrafiltration
Which of the following forms cationic micelles above certain concentration?
1. Urea
2. Cetyltrimethyylammonium bromide
3. Sodium dodecyl sulphate
4. Sodium acetate
Fog is an example of
1. Solid dispersed in gas
2. Liquid dispersed in gas
3. Liquid dispersed in solid
4. Solid dispersed in liquid
Liquid -liquid sol is known as
1. aerosol
2. foam
3. emulsion
4. gel
The colloidal system consisting of a liquid adsorbate in a solid adsorbent is termed as
1. aerosol
2. foam
3. emulsion
4. gel
When dispersed phase is liquid and dispersion medium is gas , then the colloidal system is called
1. Smoke
2. Clouds
3. Emulsion
4. Jellies
A liquid is found to scatter a beam of light but leaves no residue when passed through the filter paper. The liquid can be described as
1. A suspension
2. Oil
3. A colloidal sol
4. True solution
Which of the following statements is not correct ?
1. A colloidal solution is a heterogenous two-phase sysytem
2. Silver sol in water is an example of lyophilic solution
3. Metal hydroxides in water are examples of lyophobic solution
4. Liquid-liquid colloidal solution is noy a stable system
Size of colloidal particles may range from
1. 1 to 1000nm
2. 10 to 100pm
3. 1 to 100 $μ$ m
4. 1 to 10mm
Which of the following is a hydrophilic colloidal sol ?
1. Barium sulphate sol
2. Arsenious sulphide sol
3. Starch sol
4. Silver iodide sol
Which charcteristic is true in respect of colloidal particle?
1. They always have two phases
2. They are only in liquid state
3. They cant be electrolysed
4. They are only hydrophilic
In which of the following system the dispersed phase dispersion medium are both solid ?
1. Foal
2. Dust storm
3. Coloured glass
4. Paints
Which of the following represents a multimolecular colloidal particles?
1. Starch
2. A sol of gold
3. Proteins
4. Soaps
Size of colloidal particles is
1. 1 to 10 $Å$
2. 20 to 50 $Å$
3. 10 to 1000 $Å$
4. 1 to 280 $Å$
Which of the following represents a macromolecular colloidal particles ?
1. Solution of gold
2. Cellulose
3. Soaps
4. Synthetic detergents
$A s_{2} S_{3}$ sol has negative charge . Capacity to precipitate it ia highest in
1. $A l C l_{3}$
2. $N a_{3} P O_{4}$
3. $C a C l_{2}$
4. $K_{2} S O_{4}$
The redispersal of a freshly precipitated substance into a sol by the addition of an electrolyte in common is known as
1. Agregation
2. Condensation
3. Coagulation
4. Peptization
Which of the following is most effective in coagulating a ferric hydroxide sol?
1. KCl
2. $K N O_{3}$
3. $K_{2} S O_{4}$
4. $K_{3} [F e (C N)_{6}]$
The minimum concentration of an electrolyte required to cause coagulation or floculation of a sol is called its flocculayion value.It is expressed in
1. $m o l L^{- 1}$
2. $g L^{- 1}$
3. $m i c r o m o l e s L^{- 1}$
4. $e q u i v a l e n t L^{- 1}$
A gel os converted inot a sol by shaking it with a dispersion medium after some time it again becomes gel. This property is called
1. Weeping
2. Thixotropy
3. Syneresis
4. None of these
Which of the following electrolytes is a least effective in causing flocculation of ferric hydroxide sol?
1. $K_{4} [F e (C N)_{6}]$
2. $K_{2} C r O_{4}$
3. $K B r$
4. $K_{2} S O_{4}$
In which of the following Tyndall effect is not observed?
1. Suspension
2. Emulsion
3. Sugar solution
4. Gold sol
Sky looks blue due to
1. Dispesion effect
2. Reflection
3. Transmission
4. Scattering
On addition of 1ml solution of 10% NaCl to 10ml gold sol i the presence of 0.25g of starch , the coagultion is just prevented .Starch has the following gold number
1. 0.025
2. 0.25
3. 0.5
4. 250
The average molecular mass of colloidal can be determined by
1. Tyndall effect
2. Boiling of colloidal
3. Osmotic pressure measurement
4. Flocculation value
Ferric hydroxide sol is ppositively charged colloid. The coagaulating power of $N O_{3}^{-}, S O_{4}^{2 -} a n d P O_{4}^{3 -}$ ions would be in the order
1. $N O_{3}^{-} > S O_{4}^{2 -} > P O_{4}^{3 -}$
2. $S O_{4}^{2 -} > N O_{3}^{-} > P O_{4}^{3 -}$
3. $P O_{4}^{3 -} > S O_{4}^{2 -} > N O_{3}^{-}$
4. $N O_{3}^{-} = S O_{4}^{2 -} = P O_{4}^{3 -}$
A negatively charged suspension of clay in water will need for precipitation the minimum amount of
1. Aluminium chloride
2. Potassium sulphate
3. Sodium hydroxide
4. Hydrochloric acid
Which type of property is the Brownian movement of colloidal sol?
1. Electrical
2. Optical
3. Mechanical
4. Colligative
Movement of colloidal particles under the influence of electrostatic filed is
1. Electrophoresis
2. Electrolysis
3. Dialysis
4. Ionisation
Which of the following substances gives a postively charged sol?
1. Gold
2. A metal sulphite
3. Ferric hydroxide
4. An acidic dye
Which of the following is not represented by sols?
1. Adsorption
2. Tyndall effect
3. Flocculation
4. Paramagnetism
Which of the following electrolytes have maximum coagulating power?
1. $C C l_{4}$
2. $Z n C l_{2}$
3. $K C l$
4. $N a C l$
Arsenic (III) sulphide forms a sol with negative charge . Which of the following ionic substances should be most effective in coagulating the sol?
1. KCl
2. $M g C l_{2}$
3. $A l_{2} (S O_{4})_{3}$
4. $N a_{3} P O_{4}$
Tyndall phenomenon is exhibited by
1. NaCL solution
2. Starch solution
3. Urea solution
4. $F e C l_{3}$
Milk can be preserved by adding a few drops of
1. Formic acid solution
2. Formaldehyde solution
3. Acetic acid solution
4. Acetaldehyde solution
The presence of colloidal particles of dust in air imparts blue colur to the sky. This is due to
1. Absorption of light
2. Reflection of light
3. Refraction of light
4. Scattering of light
Property of the colloidal solution is due to
1. NAture of the dispersed phase
2. Nature of the dispersion medium
3. Physical state of the dispersed phase
4. Temperature of the system
Smoke has generally blue tinge. It is due to
1. Scattering
2. Coagulation
3. Brownian motion
4. Electro-osmosis
Bleeding is stopped by the application of ferric chloride.This is because
1. Ferric chloride seal the blood cells
2. Blood starts flowing in the other direction
3. Blood is coagulted and blood vessel is sealed
4. None of these
Gold number is assoociated with
1. Only lyophobic colloids
2. Only lyophilic colloids
3. Both lyophobic and lyophilic colloids
4. None of these
For coagulating $A s_{2} S_{3}$ colloidal sol, which of the following will have the lowest coagulation value
1. NaCl
2. KCl
3. $B a C l_{2}$
4. $A l C l_{3}$
Which one of the following substance gives a positively charged sol?
1. Gold
2. A metal sulphide
3. Ferric hydroxide
4. An acidic dye
Colloidal solution of arsenious sulphide is coagulted by
1. Addition of electrolyte
2. Addition od non-electrolyte
3. Addition of solid $A s_{2} S_{3}$
4. None of these
A negatively charged suspension of clay in water will need for precipitation the minimum anount of
1. Aluminium chloride
2. Potassium sulphate
3. Sodium hydroxide
4. Hydrochloric acid
If some gelatin is mixed in colloidal solution of gold , then it does
1. Coagulation of gold
2. Peptization of gold
3. Protection of gold sol
4. Protection of gelatin
"Delta" at the rivers are formed due to
1. Peptization
2. Coagulation
3. Hydrolysis
4. Precipitation
The ability of ion to bring about coagultion of a given colloidal solution depends upon
1. Its size of ion
2. The magnitude of charge
3. The sign of charge
4. Both magnitude and sign of charge
A coagulating agent frequently added to water to remove the suspended and colloidal impurities is
1. Mohr salt
2. Alum
3. Bleaching powder
4. Copper sulphate
Ferric chloride is applied to stop bleeding cur because
1. $F e^{3 +}$ ion coagultes blood, which is a negatively charged sol
2. $F e^{3 +}$ ion coagulates blood, which id positively charged sol
3. $C l^{-}$ ion coagulates blood, which is positively charged sol
4. $C l^{-}$ ion coagulates blood , which is a negatively charged sol
Which of the following colloids are formed when hydrogem sulphide gas is passed through a cold solution of arsenious oxide ?
1. $A s_{2} S_{3}$
2. $A s_{2} O_{3}$
3. $A s_{2} S$
4. $A s_{2} H_{2}$
An arsenious sulphide sol carries a negative charge.The maximum precipitating power for this sol is possessed by
1. $K_{2} S O_{4}$
2. $C a C l_{2}$
3. $N a_{3} P O_{4}$
4. $A l C l_{3}$
Alum helps in purifying water by
1. Forming Si complex with clay particles
2. Sulphate part which combines with the dirt and removes it
3. Aluminium which coagultes the mud and particles
4. Making mud water soluble
Maximum coagulation power is in
1. $N a^{+}$
2. $B a^{+ +}$
3. $A l^{+ + +}$
4. $S n^{+ + + +}$
On adding few drops of dilute HCl or $F e C l_{3}$ to freshly precipitated ferric hydroxide a red coloured colloidal solution is obtained . The phenomenon is known as
1. Peptisation
2. Dialysis
3. Protective action
4. Dissolution
The coagulation of 10 $C m^{3}$ Gold sol by 1ml 10% NaCl solution is completely prevented by addition of 0.025g of starch to it .The gold number of starch is
1. 0.025
2. 0.25
3. 2.5
4. 25
Gold sol is an electronegative sol.The amount electrolyte required to coagulte a certain amount of gold sol is minimum in the case
1. $C a C l_{2}$
2. NaCl
3. $A l C l_{3}$
4. $N a_{2} S O_{4}$
If gold number of A,B,C and D are 0.005,0.5 and 5 respectively , then which of the followin will have the highest protective power
1. A
2. B
3. C
4. D
Purple of Cassius is
1. Colloidal solution of gold
2. Colloidal solution of silver
3. Colloidal solution of platinum
4. Oxyacids of gold
Gold number is maxiumum for the lyophobic sol is
1. Gelatin
2. Haemoglobin
3. Sodium oleate
4. Potato starch
Which of of the following ions is most effective in the coagulation of ferric hydroxide solution?
1. $C l^{-}$
2. $B r^{-}$
3. $N a^{3} P O_{4}$
4. $M g C l_{2}$
Which of the following will have the highest coagulating power for $A s_{2} S_{3}$ colloid ?
1. $P O_{4}^{3 -}$
2. $S O_{4}^{2 -}$
3. $A l^{3 +}$
4. $N a^{+}$
Point out the false statement
1. Brownian movement and Tyndall effect is shown by colloidal system
2. Gold number is a measure of the protective power of lyophilic colloid
3. The colloidal solution of a liquid is called as gel
4. Hardy-Schulze rule is related with coagulation
For coagulting $A s_{2} S_{3}$ colloidal sol , which of the following will have the lowest coagultion value
1. NaCl
2. KCl
3. $B a C l_{2}$
4. $A l C l_{3}$
The density of gold is $19 g / c m^{3}$ .If $1.9 \times 10^{- 4}$ of gold is dispersed in one litre of water to give a sol having spherical gold particles of radius 10nm, then number of gold particles per $m m^{3}$ of the sol will be
1. $1.9 \times 10^{12}$
2. A solid is dispersed in liquid
3. A gas dispersed in liquid
4. Some sugar is dispersed in water
Milk is a colloid in which
1. A liquid is dispersed in liquid
2. A solid is dispersed in liquid
3. A gas dispersed in liquid
4. Some sugar is dispersed in water
Tyndall effect in colloidal solution is due to
1. Scattering of light
2. Reflection of light
3. Absorption of light
4. Presence of electrically charged particles
Small liqiud droplets dispersed in another liquid is called
1. Suspension
2. Emulsion
3. Gel
4. True solution
Collidal solution of arsenious sulphide is coagulated by
1. Addittion of electrolyte
2. Addition of non electrolyte
3. Addition of solid $A s_{2} S$
4. None of these
Peptisation is:
1. conversion of a colloidal into precipitate form
2. conversion of precipitate into colloidal sol
3. conversiom of metal into colloidal sol by passage of electriv current
4. conversion of colloidal sol into macromolecules
Which of the folloiwng is property of colloid?
1. Scattering of light
2. They show attraction
3. Dialysis
4. Emulsion
If some gelatin is mixed in colloidal solution of gols , then it does
1. Coagulation of gold
2. Peptization of gold
3. Protection of gold sol
4. Protection of gelatin
Gold number of lyophilic sol is such property that
1. the larger its value , the greater is the peptising power
2. the lower its value , the greater is the peptising power
3. the lower is value , the greater is protecting power
4. the larger its value , the greater is the protecting power
Whipped cream is an example of
1. Dispersion medium: Gas
  
  Dispersed phase : Liquid
2. Dispersion medium: Liquid
  
  Dispersed phase : Gas
3. Dispersion medium: Liquid
  
  Dispersed phase :Liquid
4. Dispersion medium: Liquid
  
  Dispersed phase : Solid
Protective sols are
1. Lyophilic
2. Lyophobic
3. Both lyophilic and lyophobic
4. none of these
A coagulating agent frequently added to water to remove the suspended and colloidal impurities is
1. Mohr salt
2. Alum
3. Bleaching powder
4. Copper sulphate
Alum purifies muddy water by
1. Dialysis
2. Absorption
3. Coagulation
4. Formin a true solution
Which of the following can act as protective colloids?
1. Hydrophobic sols
2. Hydrophilic sol
3. Gold sol
4. none of these
Toilet soap is mixture of
1. Calcium and sodium of fatty acids
2. Fatty avids and glycerol
3. Sodium salts of fatty acids
4. Potassium salt of fatty acids
Which of the following ions is most effective in the coagulation of an arsenious sulphide solution ?
1. $K^{+}$
2. $M g^{2 +}$
3. $A l^{3 +}$
4. C
Platinised asbestos helps in the formation of $S O_{3}$ form $S O_{2}$ and $O_{2}$ . But if even a small amount of $A s_{2} O_{3}$ is present the platinised asbestos does not help in the formation of $S O_{3}$ . $A s_{2} O_{3}$ acts here as a/an
1. positive catalyst
2. negative catalyst
3. autocatalyst
4. poison
A catalyst is a substance which
1. Alters the equilibrium in a reaction
2. Is always in the same phase as the reactants
3. Participates in the reaction and provides easier pathway for the same
4. Does not participate in the reaction but speeds it up
The decomposition of hydrogen peroxide can be slowed by the addition of a small amount of acetamide. The latter acts as a
1. Detainer
2. Stopper
3. Promoter
4. Inhibitor
When $K C l O_{3}$ is heated , it decomposes into KCl+ $O_{2}$ . If some $M n O_{2}$ is added , the reaction goes much faster because
1. $M n O_{2}$ decomposes to give $O_{2}$
2. $M n O_{2}$ provodes heat by reacting
3. Better contact is provided by $M n O_{2}$
4. $M n O_{2}$ acts as a catalyst
Which is universally correct for catalyst?
1. A catalyst remain unchanges chemically at the end of chemical reaction
2. A catalyst takes part in a chemical reaction
3. All kinds of catalyst undergo catalyst poisoning
4. A catalyst physically changes at the end of the reaction
In the redox reaction
$2 M n O_{4}^{-} + 5 C_{2} O_{4}^{2 -} + 16 H^{+} \Leftrightarrow 2 M n^{2 +} + 10 C O_{2} + 8 H_{2} O$

The ion acting as a autocatalyst is
1. $M n O_{4}^{-}$
2. $C_{2} O_{4}^{2 -}$
3. $H^{+}$
4. $M n^{2 +}$
In the reaction $2 S O_{2} + O_{2} \to_{A s_{2} O_{3}}^{P t} 2 S O_{3}, A s_{2} O_{3}$ acts as a
1. Autocatalyst
2. Poison
3. Promotor
4. Positive catalyst
Which one is false in the following statement ?
1. A catalyst is specific in its action
2. A very small amount of the catalyst alters the rate of a reaction
3. The number of free vacancies on the surfcae of the catalyst increases on sub-division
4. Ni used as a catalyst in the manufacture of ammonia
A catalyst increases rate of raection by :
1. Decreasing enthalpy
2. Decreasing internal energy
3. Decreasing activation energy
4. Increasing activation enerrgy
Which of the following types of metals form the most efficient catalysts ?
1. Alkali metals
2. Alkaline earth metals
3. Transition metals
4. All of these
Formation of ammonia from $H_{2} a n d N_{2}$ by Haber's process using Fe is an example of
1. Heterogenous catalysis
2. Homogenous catalysis
3. Enzyme catalysis
4. Non-catalytic process
What is the role of a catalyst in a catalysed reaction?
1. Lowers the activation energy
2. Increases the activation energy
3. Affects the free energy change
4. Affects the enthalpy change
The catalyst used in the contact process for manufacturing of sulphuric acid is
1. Copper
2. Iron/aluminium oxide
3. Vanadium pentoxide
4. Platinized asbestos
The role of a catalyst in reversible reaction is to
1. Increase the rate of forward reaction
2. Decrease the rate of backward reaction
3. Alter the equillibrium constant of the reaction
4. Allow the equillibrium to be achieved quickly
Which of the following catalyses the conversion of glucose into ethanol ?
1. Zymase
2. Invertase
3. Maltase
4. Diastase
Hydrolysis of ethyl acetate is catalysed by aqueous
1. $N a_{2} S O_{4}$
2. $N a_{2} S O_{4}$
3. $H_{2} S O_{4}$
4. $B a S O_{4}$
A catalst
1. Increases the free energy change in the reaction
2. Decreases the free energy change in the reaction
3. Does not increase or decrease the free energy change in the reaction
4. Can either increase or decrease the free energy change depending on what catalysr we use
Which of the following is used as a catalyst in the manufacture of toluene from benzene with $C H_{3} C l$ ?
1. Ni
2. Anhydrous $A l C l_{3}$
3. Pd
4. Pt
Hydrolysis of ethyl acetate is catalysed by aqueous
1. $N a_{2} S O_{4}$
2. $K_{2} S O_{4}$
3. $H_{2} S O_{4}$
4. $B a S O_{4}$
In the reversible reaction a catalyst is the substance which
1. Increases the rate of the forward recation
2. Decreases the value of enthalpy change in the reaction
3. Reduces the time required for reaching the equilibrium state in the reaction
4. Decreases thw rate of the reverse reaction
The components of Zeiflr-Natta catalyst , used in the polymerisation of proylene ,are
1. $T i C l_{3} + A l (C_{2} H_{5})_{3}$
2. $T i C l_{4} + A l (C_{2} H_{5})_{3}$
3. $T i (C_{2} H_{5})_{3} + A l C l_{3}$
4. $T i (C_{2} H_{5})_{4} + A l C l_{3}$
In the reversible reaction a catalyst is the substance which
1. Increases the rate of the forward reaction
2. Decreases the value of enthalpy change in the reaction
3. Reduces the time required for reacting the equilibriumstate in the reaction
4. Decreases the rate of the reverse reaction
A catalyst is used to
1. Increase the product
2. Increase or decrease the rate of the reaction
3. Increase or decrease the products
4. Decrease the products
The transition metal used as a catalyst is
1. Nickel
2. Platinum
3. Cobalt
4. All of these
Which of the following reaction is catalysed by enzyme maltase?
1. $S t a r c h \to m a l t o s e$
2. $M a l t o s e \to G l u \cos e$
3. $L a c t o s e \to m a l t o s e$
4. $M a l t o s e \to G l u \cos e + F r u c t o s e$
The efficiency of an enzyme in catalysing reaction is due to its capacity
1. To form a strong enzyme -substrate complex
2. To decrease the bond energies of substrate molecule
3. To change the shape of the substrate molecule
4. To lower the activation energy of the reaction
Which of the following is true about catalyst ?
1. It initiates reaction
2. It changes equillibrium point
3. It increases average kinetic energy
4. It accelarates the rate of reaction
In whch of the following process , platinum is used as a catalyst ?
1. Oxidation of ammonia to form nitric acid
2. Hardening of oils
3. Production of synthetic rubber
4. Synthesis of methanol
In the Ostwald's process for the manufacture of $H N O_{3}$ , the catalyst used is
1. Mo
2. Fe
3. Ni
4. Pt
Formation of ammonia from $H_{2} a n d N_{2}$ Haber,s process using Fe is an example of
1. Heterogenous catalysis
2. Homogenous catalysis
3. Enzyme catalysis
4. Non-catalytic process
Amongst the following chemical reactions, the one representing homogenous catalysis is
1. $N_{2} (g) + 3 H_{2} (g) \overset{F e}{\to} 2 N H_{3} (g)$
2. $2 S O_{2} (g) + O_{2} \overset{2 N O}{\to} 2 S O_{3} (g) + 2 N O (g)$
3. $C O_{} (g) + 3 H_{2} \overset{N i}{\to} C H_{4} (g) + H_{2} O$
4. $2 S {O_{2}}_{} (g) + O_{2} \overset{V_{2} O_{5}}{\to} 2 S O_{3} (g)$
Which of the following forms cationic micelles above certain concentrations ? (AIPMT/NEET 2004)
1. Sodium dodecyl sulphate
2. Urea
3. Sodium acetate
4. Cetyl trimethyl ammonium bromide
If x is amount of adsorbate and m is amount of adsorbent which of the following relations is relted to adsorption (AIPMT/NEET 2006)
1. $\frac{x}{m} = P \times T$
2. $\frac{x}{m} = f (P) a t c o n s \tan t T$
3. $\frac{x}{m} = f (T) a t c o n s \tan t P$
4. $P = f (T) a t c o n s \tan t \frac{x}{m}$
The langmiur adsorption isotherm is deduced using the assumption(AIPMT/NEET 2007)
1. The adsorption sites are equivalent in their ability to adsorb the particles
2. The heat of adsorption varies with coverage
3. The adsorbed molecules interact with each other
4. The adsorption takes place in multilayers
Catalyst (AIPMT/NEET 2010)
1. Lowers activaation energy
2. increases activation energy
3. may increse or may decrease activation energy
4. brings out equilibrium
The catalytic activity of transistions metals and their compounds is ascribed mainly to(AIPMT/NEET2010)
1. their magnetic behvaiour
2. their unfilled d-orbitals
3. their ability to adopt variable oxidation states
4. their chemical reactivity
In Freundlich adsorption isotherm , the value of $\frac{1}{n}$ is (AIPMT/NEET2012)
1. 1 in case of physical adsorption
2. 1 in case of chemisorption
3. between 0 and 1 in all cases
4. between 2 and 4 in all cases
Which one of the following statements is incorrect about enzyme catalysis? (AIPMT/NEET 2012)
1. ENzymes are denatured by ultraviolet rays and at high temperature
2. Enzymes are least reactive at optimum temperature
3. Enzymes are mostly protenious in nature
4. Enzyme action is specific
The protecting power of lyophilic colloidal solution is expressed in terms of (AIPMT/NEET 2012)
1. Critical micelle concentration
2. Oxidation number
3. coagulation vale
4. gold number
Which property of colloids is not dependent on the , charge on colloidal particles ? (AIPMT/NEET 2014,2015)
1. Tyndall effect
2. Coagulation
3. Electrophoresis
4. Electro-osmosis
Which one of the following characteristic is associated with adsoprtion ?(AIPMT/NEET 2016-phase1)
1. $∆ G a n d ∆ S$ are negative but $∆ H$ is positive
2. $∆ G$ is negative but $∆ H a n d ∆ S$ are positive
3. $∆ H, ∆ S a n d ∆ G$ all are negative
4. $∆ G a n d ∆ H$ are negative but $∆ S$ is positive
The pressure of $H_{2}$ required to make the potential of $H_{2}$ electrode zero in pure water at 298K is (AIPMT/NEET 2016pgase-1)
1. $10^{- 4} a t m$
2. $10^{- 14} a t m$
3. $10^{- 12} a t m$
4. $10^{- 10} a t m$
Fog is a colloidal solution of (AIPMT/NEET phase-1)
1. Gas in gas
2. Liquid in gas
3. Gas in liquid
4. Solid in gas
Physical adsorption is inversely proportional to the (AIIMS 2001)
1. volume
2. Concentration
3. temperature
4. all of these
$C_{12} H_{22} O_{11} + H_{2} O \overset{d i l . H_{2} S O_{4}}{\to} C_{6} H_{12} O_{6} (a q) + C_{6} H_{12} O_{6} g l u \cos e f r u c t o s e$ (AIIMS 2001)
in this reaction, dilute $H_{2} S O_{4}$ is called as
1. homogenous catalysis
2. homogeneous catalyst
3. heterogenous catalysis
4. heterogenous catalys
Catalyst used in hydrogenation of oils is (AIIMS 2002)
1. Pt
2. Mo
3. Fe
4. Ni
Catalyst used in the oxidation of $S O_{2} \to S O_{3}$ (AIIMS 2003)
1. Nickel
2. $Z n O . C r_{2} O_{3}$
3. $V_{2} O_{5}$
4. Iron
Which requires catalyst? (AIIMS 2003)
1. $S + O_{2} \to S O_{2}$
2. $2 S O_{2} + O_{2} \to 2 S O_{3}$
3. $C + O_{2} \to C O_{2}$
4. All
The stability of lyophillic colloids is due to (AIIMS 2004)
1. charge on their particles
2. a layer of dispersion medium on their particles
3. the samller size of their particles
4. the large size of their particles
Size of colloidal particles varies from(AIIMS 2005)
1. $10^{- 7} t o 10^{- 9} m$
2. $10^{- 9} t o 10^{- 17} m$
3. $10^{- 5} t o 10^{- 7} m$
4. $10^{- 4} t o 10^{- 10} m$
On adding few drops of dilute HCl or $F e C l_{3}$ to freshly precipitated ferric hydroxide a red coloured colloidal solution is obtained .The phenomenon is known as (AIIMS 2007)
1. peptization
2. dialysis
3. protective action
4. dissolution
Bredig's arc method cannot be used to prepare colloidal solution of which of the following ? ( AIIMS 2009)
1. Pt
2. Fe
3. Ag
4. Au
Which one of the following is not a surfactant? (AIIMS 2011)
1. $C H_{3} - (C H_{2})_{15} - {N^{+} - C H_{3} B r^{-}}_{\overset{|}{C H_{3}}}^{\overset{C H_{3}}{|}}$
2. $C H_{3} - (C H_{2})_{14} - C H_{2} - N H_{2}$
3. $C H_{3} - (C H_{2})_{16} - C H_{2} O S O_{2}^{-} N a^{+}$
4. $C H_{3} - (C H_{2})_{14} - C H_{2} - C O O^{-} N a^{+}$
Assertion : Sky appears blue colour
Reason: Colloidal particles of dudt scatter blue light (AIIMS 2006)
1. If both the assertion and reason are true but reason is a true explanation of the assertion
2. If both the assertion and reason are true but reason is not the correct explanation of the assertion
3. If the assertion is true but reason is false
4. If the assertion is false but reason is true
Assertion:The micelle fromed by sodium stearate in water has $- C O O^{-}$ groups at the surface
Reason: Surfcae tension of water is reduced by the adition of stearate (AIIMS 2008)
1. If both the assertion and reason are true but reason is a true explanation of the assertion
2. If both the assertion and reason are true but reason is not the correct explanation of the assertion
3. If the assertion is true but reason is false
4. If the assertion is false but reason is true
Assertion : Aqueous gold colloidal solution is red in colour
Reason: The colour arises due to scattering of light by colloidal gold particles
(AIIMS 2010)
1. If both the assertion and reason are true but reason is a true explanation of the assertion
2. If both the assertion and reason are true but reason is not the correct explanation of the assertion
3. If the assertion is true but reason is false
4. If the assertion is false but reason is true