Electrochemistry

Electrode potential of $Z n^{2 +} / Z n$ is 0.76 V and that of $C u^{2 +} / C u$ is +0.34 V. The EMF of the cell constructed between two electrodes is [AIPMT / NEET 2001]
1. 1.10 V
2. 0.42 V
3. - 1.1 V
4. - 0.42 V
The cell reaction of a cell is $M g (s) + C u^{2 +} (a q) \to C u (s) + M g^{2 +} (a q)$
If the standard reduction potentials of Mg and Cu are - 2.37 and + 0.34 V respectively. The emf of the cell is [AIPMT / NEET 2002]
1. 2.03 V
2. - 2.03 V
3. + 2.71 V
4. - 2.71 V
On the basis of the information available from the reaction
$\frac{4}{3} A l + O_{2} \to \frac{2}{3} A l_{2} O_{3}, ∆ G = 0.827 k J m o l^{- 1} o f O_{2},$
the minimum emf required to carry out an electrolysis of $A l_{2} O_{3} i s (F = 96500 C m o l^{- 1})$ . [AIPMT / NEET 2003]
1. 8.56 V
2. 2.14 V
3. 4.28 V
4. 6.42 V
The electrolytic conductance is a direct measure of [AIPMT / NEET 2003 ]
1. resistance
2. potential
3. concentration
4. dissociation
The emf of a Daniel cell at 298 K is $E_{1} Z n |Z n S O_{4} (0.01 M)| |C u S O_{4} (1.0 M)| C u$ when the concentration of $Z n S O_{4}$ is 1.0 M and that of $C u S O_{4}$ is 0.01 M, the emf changed to $E_{2}$ . What is the relationship between $E_{1} a n d E_{2}$ . [AIPMT / NEET 2003]
1. $E_{2} = 0 \neq E_{1}$
2. $E_{1} > E_{2}$
3. $E_{1} < E_{2}$
4. $E_{1} = E_{2}$
The standard electrode potential of the half cells is given below.
$Z n^{2 +} + 2 e^{-} \to Z n; E = - 7.62 V$
$F e^{2 +} + 2 e^{-} \to F e; E = - 7.81 V$
The emf of the cell $F e^{2 +} + Z n \to Z n^{2 +} + F e i s$ [AIPMT / NEET 2003]
1. 1.54 V
2. - 1.54 V
3. - 0.19 V
4. + 0.19 V
An electric current is passed through silver nitrate solution using silver electrodes. 10.79 g of silver was found to be deposited on the cathode if the same amount of electricity is passed through copper sulphase solution using copper electrodes, the weight of copper deposited on the cathode is [AIPMT / NEET 2004]
1. 6.4 g
2. 2.3 g
3. 12.8 g
4. 3.2 g
4.5 g of Al (atomic mass 27 amu) is deposited at cathode from $A l^{3 +}$ solution by a certain quantityh of charge. The volume of $H_{2}$ produced at STP from $H^{+}$ ions in solution by the same quantity of charge will be [AIPMT / NEET 2005]
1. 11.2 L
2. 44.8 L
3. 5.6 L
4. 22.4 L
A hypothetical electro-chemical cell is given as $A^{-} |A^{+} (x M)| |B^{+} (y M)| B^{-}$ . The emf measured is + 0.20 V. The cell reaction is [AIPMT / NEET 2006]
1. The cell reaction cannot be predicted
2. $A + B^{+} \to A^{+} + B$
3. $A^{+} + B \to A + B^{+}$
4. $A^{+} + e^{-} \to A; B^{+} + e^{-} \to B$
If $E_{F e^{2 + / F e}}^{0} = - 0.441 V a n d E_{F e^{3 + / F e^{2 +}}}^{0} = 0.771 V$ , the standard emf of the reaction $F e + 2 F e^{3 +} \to 3 F e^{2 +}$ will be [AIPMT / NEET 2006]
1. 1.653 V
2. 0.111 V
3. 0.330 V
4. 1.212 V
The equilibrium constant for the reaction
$C u + 2 A g^{+} (a q) \to C u^{2 +} (a q) + 2 A g; E^{0} = 0.46 V a t 2.98 K i s$ [AIPMT / NEET 2007]
1. $2.0 \times 10^{10}$
2. $3.9 \times 10^{15}$
3. $4.0 \times 10^{10}$
4. $2.4 \times 10^{10}$
On the basis of the following $E^{0}$ values, the strongest oxidizing agent is
${[F e {(C N)}_{6}]}^{4 -} \to {[F e {(C N)}_{6}]}^{3 -} + e^{-}; E^{0} = - 0.35 V$
$F e^{2 +} \to F e^{3 +} + e^{-}; E^{0} = - 0.77 V$ [AIPMT / NEET 2008]
1. $F e^{2 +}$
2. $F e^{3 +}$
3. ${[F e {(C N)}_{6}]}^{3 -}$
4. ${[F e {(C N)}_{6}]}^{4 -}$
Standard free energies of formation (in kJ / mol) at 298 K are - 237.2, - 394.4 and - 8.2 for $H_{2} O (l), C O_{2} (g)$ and pentane(g) respectively. The value of $E_{c e l l}^{0}$ for the pentane-oxygen fuel cell is [AIPMT / NEET 2008]
1. 2.0968 V
2. 1.0968 V
3. 0.0968 V
4. 1.968 V
The correct order of the mobility of the alkali metal ions in aqueous solution is [AIPMT / NEET 2008]
1. $K^{+} > R b^{+} > N a^{+} > L i^{+}$
2. $R b^{+} > K^{+} > N a^{+} > L i^{+}$
3. $L i^{+} > N a^{+} > K^{+} > R b^{+}$
4. $N a^{+} > K^{+} > R b^{+} > L i^{+}$
Kohlrausch's law states that at [AIPMT / NEET 2008]
1. Infinite dilution, each ion makes definite contribution to equivalent conductance of an electrolyte depending on the nature of the other ion of the electrolyte
2. Infinite dilution, each ion makes definite contribution to conductance of an electrolyte whatever be the nature of the other ion of the electrolyte
3. Infinite dilution, each ion makes definite contribution to equivalent conductance of an electrolyte, whatever be the nature of the other ion of the electrolyte.
4. Finite dilution, each ion makes definite contribution to equivalent conductance of an electrolyte, whatever be the nature of the other ion of the electrolyte
Given :-
$C u^{2 +} + 2^{e -} \to C u, E^{0} = 0.337 V$
$C u^{2 +} + e^{-} \to C u^{+}, E^{0} = 0.153 V$
Electrode potential, $E^{0}$ for the reaction, $C u^{+} + e^{-} \to C u$ , will be [AIPMT / NEET 2009]
1. 0.38 V
2. 0.52 V
3. 0.90 V
4. 0.30 V
$A l_{2} O_{3}$ is reduced by electrolysis at low potentials and high currents. If $4.0 \times 10^{4}$ amperes of current is passed through molten $A l_{2} O_{3}$ for 6 hours, what mass of aluminium is produced ?
(Assume 100% current efficiency. At mass of $A l = 27 g m o l^{- 1}$ ) [AIPMT / NEET 2009]
1. $1.3 \times 10^{4} g$
2. $9.0 \times 10^{3} g$
3. $8.05 \times 10^{4} g$
4. $2.4 \times 10^{5} g$
The correct value of emf of cell is given by
i) $E_{c e l l} = E_{O P} a n o d e - E_{R P} c a t h o d e$
ii) $E_{c e l l} = E_{O P} a n o d e + E_{R P} c a t h o d e$
iii) $E_{c e l l} = E_{R P} a n o d e + E_{R P} c a t h o d e$
iv) $E_{c e l l} = E_{O P} a n o d e - E_{O P} c a t h o d e$ [AIPMT / NEET 2010]
1. (iii) and (i)
2. (i) and (ii)
3. (iii) and (iv)
4. (ii) and (iv)
For the reduction of silver ions with copper metal, the standard coil potential is 0.46 V at $25 ° C$ . The value of Gibbs energy $∆ G °$ will be [AIPMT / NEET 2010]
1. - 89.0 kJ
2. - 89.0 J
3. - 44.5 kJ
4. - 98.0 kJ
An increases in equivalent conductivity of strong electrolyte with dilution is mainly due to [AIPMT / NEET 2010]
1. increase in ionic molility of ions
2. 100% ionisation of electrolyte at normal dilution
3. increases in both, i.e. number of ions and ions mobility
4. increases in number of ions
The electrode potentials for $C u^{2 +} (a q) + e^{-} \to C u^{+} (a q) a n d C u^{+} (a q) + e^{-} \to C u^{+} (s)$ are +0.15 V and +0.50V respectively. The value of $E_{C u^{2 +} / C u}^{0}$ will be [AIPMT / NEET 2011]
1. 0.150 V
2. 0.325 V
3. 0.500 V
4. 0.650 V
Standard electrode potential for $S n^{4 +} / S n^{2 +}$ couple is + 0.15 V and that for the $C r^{3 +} / C r$ couple is - 0.74 V. These two couples in their standard state are connected to make a cell. The cell potential will be [AIPMT / NEET 2011]
1. + 1.83 V
2. + 1.19 V
3. + 0.18 V
4. + 0.89 V
Standard electrode potential of three metal X, Y and Z are - 1.2 V, + 0.5 V and - 3.0 V respectively. The reducing power of these metals will be [AIPMT / NEET 2011]
1. $X > Y > Z$
2. $Y > Z > X$
3. $Y > X > Z$
4. $Z > X > Y$
If the $E_{c e l l}^{0}$ or a given reaction has a negative value then which of the following gives the correct relationship for the value of $∆ G ° a n d K_{e q}$ ? [AIPMT / NEET 2011]
1. $∆ G ° > 0; K_{e q} < 1$
2. $∆ G ° > 0; K_{e q} > 1$
3. $∆ G ° < 0; K_{e q} > 1$
4. $∆ G ° < 0; K_{e q} < 1$
Standard reduction potentials of the half reactions are given below :
$F_{2} (g) + 2^{e -} \to 2 F^{-} (a q); E^{0} = + 2.85 V$
$C l_{2} (g) + 2^{e -} \to 2 C l^{-} (a q); E^{0} = + 1.36 V$
$B r_{2} (i) + 2^{e -} \to 2 B r^{-} (a q); E^{0} = + 1.06 V$
$I_{2} (s) + 2^{e -} \to 2 I^{-} (a q); E^{0} = + 0.53 V$
The strongest oxidizing and reducing agents respectively are [AIPMT / NEET 2012]
1. $F_{2} a n d I^{-}$
2. $B r_{2} a n d C l^{-}$
3. $C l_{2} a n d B r^{-}$
4. $C l_{2} a n d I^{-}$
Limiting molar conductivity of $N H_{4} O H, i . e . ∆_{m} (N H_{4} O H)$ is equal to [AIPMT / NEET 2012]
1. $∆ m (N H_{4} O H) + ∆_{m} (N H_{4} C l) - ∆_{m} (H C l)$
2. $∆ m (N H_{4} C l) + ∆_{m} (N a O H) - ∆_{m} (N a C l)$
3. $∆ m (N H_{4} C l) + ∆_{m} (N a C l) - ∆_{m} (N a O H)$
4. $∆ m (N H_{4} O H) + ∆_{m} (N a C l) - ∆_{m} (N a_{4} C l)$
Molar conductivity $[∆_{m}]$ at infinite dilution NaCl, HCl and $C H_{3} C O O N a$ are 126.4, 425.9 and 91.0 S $C m^{2} m o l^{- 1}$ rrespectively. $∆_{m} f o r C H_{3} C O O H$ will be [AIPMT / NEET 2012]
1. $425.5 S C m^{2} m o l^{- 1}$
2. $180.5 S C m^{2} m o l^{- 1}$
3. $290.8 S C m^{2} m o l^{- 1}$
4. $390.5 S C m^{2} m o l^{- 1}$
A button cell used in watches functions as following
$Z n (s) + A g_{2} O (s) + H_{2} O (l)$
$2 A g (s) + Z n^{2 +} (s) + 2 O H^{-} (a q)$
If half cell potentials are
$Z n^{2 +} (a q) + 2 e^{-} \to Z n (s); E^{0} = - 0.76 V$
$A g_{2} O (s) + H_{2} O (l) + 2 e^{-} \to 2 A g (s) + 2 O H^{-} (a q); E^{0} = 0.34 V$
The cell potential will be [AIPMT / NEET 2013]
1. 0.42 V
2. 0.84 V
3. 1.10 V
4. 1.34 V
At $25 ° C$ molar conductance of 0.1 molar aqueous solution of ammonium hydroxide is $9.54 o h m^{- 1} c m^{2} m o l^{- 1}$ and at infinite dilution its molar conductance is $238 o h m^{- 1} c m^{2} m o l^{- 1}$ . The degree of ionisation and temperature is [AIPMT / NEET 2013]
1. 20.800 %
2. 4.008 %
3. 40.800 %
4. 2.080 %
A hydrogen gas electrode is made by dipping platinum wire in a solution of HCl of pH = 10 and by passing hydrogen gas around the platinum wire at one atm pressure. The oxidation potential of electrode would be ? [AIPMT / NEET 2013]
1. 0.59 V
2. 0.118 V
3. 1.18 V
4. 0.059 V
When 0.1 mol $M n O_{4}^{2 -}$ is oxidised the quantitty of electricity required to completely oxidise $M n O_{4}^{2 -}$ to $M n O_{4}^{-}$ is [AIPMT / NEET 2014]
1. 96500 C
2. 2 x 96500 C
3. 9650 C
4. 96.50 C
A device that converts energy of combustion of fuels like hydrogen and methane, directly into electrical energy is known as [AIPMT / NEET 2015]
1. dynamo
2. Ni-Cd cell
3. fuel cell
4. electrolytic cell
Aqueous solution of which of the following compounds is the best conductor of electric current ? [AIPMT / NEET 2015 Re]
1. Ammonia, $N H_{3}$
2. Fuctose, $C_{6} H_{12} O_{6}$
3. Acetic acid, $C_{2} H_{4} O_{2}$
4. Hydrochloric acid, HCl
During the electrolysis of an electrolyte, the number of ions produced, is directly proportional to the [AIIMS 2001]
1. time consumed
2. electro-chemical equivalent of electrolysis
3. quantity of electricity passed
4. mass opf electrons
During the electrolysis of fused NaCl which reaction occurs at anode ? [AIIMS 2002]
1. Chloride ions are oxidized
2. Chloride ions are reduced
3. Sodium ions are oxidised
4. Sodium ions are reduced
In electrolysis of aqueous copperr sulphate, the gas at anode and cahode is [AIIMS 2002]
1. $O_{2} a n d H_{2}$
2. $S O_{2} a n d H_{2}$
3. $H_{2} a n d O_{2}$
4. $S O_{3} a n d O_{2}$
Use of electrolysis is [AIIMS 2003]
1. electroplating
2. electrorefining
3. both (a) and (b)
4. None of these
During electrolysis, the species discharged at cathode are [AIIMS 2003]
1. ions
2. cation
3. anion
4. all of these
Electrolysis of molter anhydrous calcium chloride produces
1. calcium
2. phosphorus
3. sulphur
4. sodium
Amount of electricity that can deposit 108 g of silver frrom $A g N O_{3}$ solution is [AIIMS 2004]
1. 1 ampere
2. 1 coulomb
3. 1 faraday
4. none of the above
On passing one faraday of electricity through the electrolytic cells containing $A g^{+}, N i^{+ 2} a n d C r^{+ 3}$ ion solutions, the deposited Ag (At. wt. = 108) Ni (At. wt. = 59) and Cr (At. wt. = 52) is [AIIMS 2005]
1. Ag (108 g), Ni (29.5 g), Cr (17.3 g)
2. Ag (108 g), Ni (59.0 g), Cr (52.0 g)
3. Ag (108.0 g), Ni (108.0 g), Cr (108.0 g)
4. Ag (108 g), Ni (117.5 g), Cr (166.0 g)
What is the amount of chlorine evolved when 2 ampheres of current is passed for 30 minutes in an aqueous solution of NaCl ? [AIIMS 2005]
1. 66 g
2. 1.32 g
3. 33 g
4. 99 g
The number of electrons required to deposit 1 g atom of aluminium (At. wt. = 27) from a solution of aluminium chloride will be (where N is Avogadro's number) [AIIMS 2005]
1. 1 N
2. 2 N
3. 3 N
4. 4 N
From the solution of which of the following one faraday of electricity will liberate one gram atom of metal [AIMS 2006]
1. NaCl
2. $B a C l_{2}$
3. $C u S O_{4}$
4. $A l C l_{3}$
If 0.5 amps current is passed through acidified silver nitrate solution for 10 minutes. The mass of silver deposited on cathode is (eq. wt. of silver nitrate = 108) [AIIMS 2006]
1. 0.235 g
2. 0.336 g
3. 0.536 g
4. 0.636 g
Charge required to liberate 11.5 g sodium is [AIIMS 2007]
1. 0.5 F
2. 0.1 F
3. 1.5 F
4. 96500 coulombs
Which of the following conducts electricity ? [AIIMS 2007]
1. Fused NaCl
2. $C O_{2}$
3. $B r_{2}$
4. Si
Which of the following shows electrical conduction ? [AIIMS 2008]
1. Potassium
2. Graphite
3. Diamond
4. Si
Which of the following statements is not applicable to electrolytic conductors ? [AIIMS 2009]
1. New products show up at the electrodes
2. Ions are responsible for carrying the current
3. Shows a positive temperature co-efficient for conductance
4. A single stream of electrons flows from cathode to anode
When electric current is passed through a cell having an electrolyte, the positive ions move towards the cathode and the negative ions move towards anode. If the cathode is pulled out of the solution [AIIMS 2009]
1. The positive and negative ions will move towards anode
2. The positive ions will start moving towards the anode, the negative ions will stop moving
3. The negative ions will continue to move towards the anode and the positive ions will stop moving
4. The positive and negative ions will start moving randomly.
Which of the following reaction is used to make a fuel cell [AIIMS 2009]
1. $C d (s) + 2 N i (O H)_{3} (s) \to C d O (s) + 2 N i (O H) + H_{2} O (l)$
2. $P b (s) + P n O_{2} (s) + 2 H_{2} S O_{4} (a q) \to 2 P b S O_{4} (s) + 2 H_{2} O (l)$
3. $2 H_{2} (g) + O_{2} (g) \to 2 H_{2} O (l)$
4. $2 F e (s) + O_{2} (g) + 4 H^{+} (a q) \to 2 F e^{2 +} (a q) + 2 H_{2} O (l)$
In electrolysis of dilute $H_{2} S O_{4}$ using platinum electrodes [AIIMS 2010]
1. $H_{2}$ is evolved at cathode
2. $N H_{3}$ is produced at anode
3. $C l_{2}$ is obtained at cathode
4. $O_{2}$ is produced
In an electro-chemical cell [AIIMS 2011]
1. potential energy changes into kinetic energy
2. kinetic energy changes into potential energy
3. Chemical energy changes into electrical energy
4. Electrical energy changes into chemical energy
Which of the following statement is true for the elctro-chemical Daniel cell ? [AIIMS 2011]
1. Electrons flow from copper electrode to zinc electrode
2. Current flow from zinc electrode to copper electrode
3. Cations move toward copper electrode which is cathode
4. Cations move toward zinc electrode
The chemical reaction, $2 A g C l (s) + H_{2} (g) \to 2 H C l (a q) + 2 A g (s)$ taking place in a galvanic cell is represented by the notation [AIIMS 2011]
1. $P t | H_{2} (g), 1 b a r | 1 M K C l (a q) | A g C l (s) | A g (s)$
2. $P t (s) + H_{2} (g), 1 b a r | 1 M K C l (a q) | | 1 M A g^{+} (a q) | A g (s)$
3. $P t (s) + H_{2} (g), 1 b a r | 1 M K C l (a q) | A g C l (s) | A g (s)$
4. $P t (s) + H_{2} (g), 1 b a r | 1 M K C l (a q) | | A g (s) | A g C l (s)$
Which one of the following metals cannot evolve $H_{2}$ from acids or $H_{2} O$ from its compounds ? [AIIMS 2012]
1. Hg
2. Al
3. Pb
4. Fe
Electrode potential of $Z n^{2 +} / Z n i s - 0.76 V$ and that of $C u^{2 +} / C u i s + 0.34 V$ . The EMF of the cell constructed between two electrodes is [AIIMS 2012]
1. 1.10 V
2. 0.42 V
3. - 1.1 V
4. - 0.42 V
Given standard electrode potentials
$F e^{+ +} + 2 e^{-} \to F e; E^{0} = - 0.440 V$
$F e^{+ + +} + 3 e^{-} \to F e; E^{0} = - 0.00036 V$
The standard electrode potential $(E^{0})$ for $F e^{+ + +} + e^{-} \to F e^{+ +}$ is [AIIMS 2013]
1. - 0.476 V
2. - 0.404 V
3. + 0.404 V
4. + 0.772 V
The cell reaction of a cell is
$M g_{(s)} + C u^{2 +} (a q) \to C u_{(s)} + M g^{2 +} (a q)$
If the standard reduction potentials of Mg and Cu are - 2.37 and + 0.34 V respectively. The emf of the cell is [AIIMS 2013]
1. 2.03 V
2. - 2.03 v
3. + 2.71 V
4. - 2.71 V
Which of the following statement is true for fuel cells ? [AIIMS 2013]
1. They are more efficient
2. They are free from pollution
3. They run till reactants are active
4. All of these
The emf of a galvanic cell with electrode potentials of silver = + 0.80 V and that of copper = + 0.34 V is [AIIMS 2014]
1. - 1.1 V
2. + 1. 1 V
3. + 0.46 V
4. - 0.76 V
Which of the following is a highly corrosive salt ? [AIIMS 2015]
1. $F e C l_{2}$
2. $P b C l_{2}$
3. $H g_{2} C l_{2}$
4. $H g C l_{2}$
The standard reduction potential $E^{0}$ for the half reaction are as
$Z n = Z n^{2 +} + 2 e^{-}; E^{0} = + 0.76 v$
$F e = F e^{2 +} + 2 e^{-}; E^{0} = + 0.41 v$
The EMF for the cell reaction $F e^{2 +} + Z n \to Z n^{2 +} + F e$ is [AIIMS 2015]
1. - 0.35 V
2. + 0.35 V
3. + 1.17 V
4. - 1.17 V
ASSERTION : The conductance measurement of an electrolytic solution is made by using two conductivity cells having different cell constants gives different values of conductance.
REASON : The conductivity of solution obtained will be different but conductivity of solution would be same. [AIIMS 2001]
1. If both the assertion and reason are true and reason is a true explanation of the assertion
2. If both the assertion and reason are true but the reason is not the correct explantion of assertion
3. If the assertion is true but reason is false.
4. If assertion is false but reason is true
ASSERTION : Conductance of a solution can be obtained by designing the apparatus based on Wheatstone bridge principle.
REASON : Meter bridge used to detect the resistance of metal wire can be used to read out the conductance of solutions. [AIIMS 2004]
1. If both the assertion and reason are true and reason is a true explanation of the assertion
2. If both the assertion and reason are true but the reason is not the correct explantion of assertion
3. If the assertion is true but reason is false.
4. If assertion is false but reason is true
ASSERTION : According to Kohlrausch's law the molar conductivity of a strong electrolyte at infinite dilution is sum of molar conductivities of its ions.
REASON : The current carried by cation and anion is always equal. [AIIMS 2007]
1. If both the assertion and reason are true and reason is a true explanation of the assertion
2. If both the assertion and reason are true but the reason is not the correct explantion of assertion
3. If the assertion is true but reason is false.
4. If assertion is false but reason is true
ASSERTION : For the Daniel cell $Z n | Z n^{2 +} | | C u^{2 +} | C u w i t h E_{c e l l} = 1.1 V$ , the application of opposite potential greater than 1.1 V results into flow of electron from Cu to Zn.
REASON : Zn is deposited at anode and Cu is deposted at Cathode. [AIIMS 2008]
1. If both the assertion and reason are true and reason is a true explanation of the assertion
2. If both the assertion and reason are true but the reason is not the correct explantion of assertion
3. If the assertion is true but reason is false.
4. If assertion is false but reason is true
ASSERTION : Rusting of iron is an example of corrosion.
REASON : Rusting of iron is decreased by acids and electrolytes. [AIIMS 2009]
1. If both the assertion and reason are true and reason is a true explanation of the assertion
2. If both the assertion and reason are true but the reason is not the correct explantion of assertion
3. If the assertion is true but reason is false.
4. If assertion is false but reason is true
ASSERTION : The electrical resistance of a column of 0.5 M NaOH solution of diameter 1 cm and length 50 cm is $5.55 x 10^{3} o h m .$ .
REASON : Its resistivity is equal to 76.234 $Ω$ cm. [AIIMS 2009]
1. If both the assertion and reason are true and reason is a true explanation of the assertion
2. If both the assertion and reason are true but the reason is not the correct explantion of assertion
3. If the assertion is true but reason is false.
4. If assertion is false but reason is true
ASSERTION : Galvanised iron does not rust.
REASON : Zinc has a more negative electrode potential than iron. [AIIMS 2010]
1. If both the assertion and reason are true and reason is a true explanation of the assertion
2. If both the assertion and reason are true but the reason is not the correct explantion of assertion
3. If the assertion is true but reason is false.
4. If assertion is false but reason is true
ASSERTION : Speeds of ions depends upon nature of ions only.
REASON : Mobility of ions depends upon mass, charge and size of ions only. [AIIMS 2011]
1. If both the assertion and reason are true and reason is a true explanation of the assertion
2. If both the assertion and reason are true but the reason is not the correct explantion of assertion
3. If the assertion is true but reason is false.
4. If assertion is false but reason is true
Faraday's law of electrolysis are related to the
1. Atomic number of cations
2. Atomic number of anion
3. Equivalent weight of the electrolyte
4. Speed of the cation
The required charge for one equivalent weight of silver deposited on cathode is
1. $9.65 \times 10^{7} C$
2. $9.65 \times 10^{4} C$
3. $9.65 \times 10^{3} C$
4. $9.65 \times 10^{5} C$
During the process of electrolytic refining of copper, some metals present as impurity settle as 'anode mud'. These are
1. Sn and Mg
2. Pb and Zn
3. Ag and Au
4. Fe and Ni
Conductivity (unit Siemens) is directly proportional to area of the vessel and the concentration of the solution in it and is inversely proportional to the length of the vessel, then the unit of the constant of proportionality is
1. $S m m o l^{- 1}$
2. $S m^{2} m o l^{- 1}$
3. $S^{- 2} m^{2} m o l$
4. $S^{2} m^{2} m o l^{- 2}$
Given $\frac{l}{a} = 0.5 c m^{- 1}$ , R = 50 ohm, N = 1.0. The equivalent conductance of the electrolytic cell is
1. $10 o h m^{- 1} c m^{2} g m e q^{- 1}$
2. $20 o h m^{- 1} c m^{2} g m e q^{- 1}$
3. $300 o h m^{- 1} c m^{2} g m e q^{- 1}$
4. $100 o h m^{- 1} c m^{2} g m e q^{- 1}$
The molar conductances of NaCl, HCl and $C H_{3} C O O N a$ at infinite dilution are 126.45, 426.16 and $91 o h m^{- 1} c m^{2} m o l^{- 1}$ respectively. The molar conductance of $C H_{3} C O O H$ at infinite dilution is
1. $201.28 o h m^{- 1} c m^{2} m o l^{- 1}$
2. $390.71 o h m^{- 1} c m^{2} m o l^{- 1}$
3. $698.28 o h m^{- 1} c m^{2} m o l^{- 1}$
4. $540.48 o h m^{- 1} c m^{2} m o l^{- 1}$
The position of some metals in the electro-chemical series in decreasing electro-positive character is given as $M g > A l > Z n > C u > A g .$ What will happen if a copper spoon is used to stir a solution of aluminium nitrate ?
1. The spoon will get coated with Al
2. An alloy of Cu and Al is formed
3. The solution becomes blue
4. There is no reaction
The standard reduction potential at 298 K for the following half reactions are given against each
$Z n^{2 +} (a q) + 2 e ⇌ Z n (s); - 0.762$
$C r^{3 +} (a q) + 3 e ⇌ C r (s); - 0.740$
$2 H^{+} (a q) + 2 e ⇌ H_{2} (g); - 0.00$
$F e^{3 +} (a q) + e ⇌ F e^{2 +} (a g); - 0.770$
Which is the strongest reducing agent ?
1. Zn(s)
2. Cr(s)
3. $H_{2} (g)$
4. $F e^{2 +} (a q)$
A solution containing one mole per litre of each $C u (N O_{3})_{2}, A g N O_{3}, H g_{2} (N O_{3})_{2} a n d M g (N O_{3})_{2}$ is being electrolysed by using inert electrodes. The values of standard electrode potentials in volts (reduction potentials) are $A g / A g^{+} = + 0.80, 2 H g / H g_{2}^{2 +} = + 0.79, C u / C u^{2 +} = + 0.34, M g / M g^{2 +} = - 2.37$ with increasing voltage, the sequence of deposition of metals on the cathode will be
1. Ag, Hg, Cu, Mg
2. Mg, Cu, Hg, Ag
3. Ag, Hg, Cu
4. Cu, Hg, Ag
When a copper wire is placed in a solution of $A g N O_{3}$ , the solution acquires blue colour. This is due to the formation of
1. $C u^{2 +} i o n s$
2. $C u^{+} i o n s$
3. Soluble complex of copper with $A g N O_{3}$
4. $C u^{-}$ ion by the reductionf Cu.
The standard reduction potential for $F e^{2 +} / F e a n d S n^{2 +} / S n$ electrodes are - 0.44 and - 0.143 volt respectively. For the given cell reaction $F e^{2 +} / S n \to F e + S n^{2 +}$ , the standard EMF is
1. + 0.30 V
2. - 0.58 V
3. + 0.58 V
4. - 0.30 V
For the redox reaction $Z n (s) + C u^{2 +} (0.1 M) \to Z n^{2 +} (1 M) + C u (s)$ taking place in a cell, $E_{c e l l}^{0}$ is 1.10 volt. $E_{c e l l}$ for the cell will be $(2.303 \frac{R T}{F} = 0.0591)$
1. 2.14 volt
2. 1.80 volt
3. 1.07 volt
4. 0.82 volt
Standard reduction electrode potentials of three metals A, B and C are respectively + 0.5 V, - 3.0 V and - 1.2 V. The reducing powers of these metals are
1. $B > C > A$
2. $A > B > C$
3. $C > B > A$
4. $A > C > B$
For a cell reaction involving a two-electron change, the standard emf of the cell is found to be 0.295 V at $25 ° C$ . The equilibrium constant of the reaction at $25 ° C$ will be
1. $1 \times 10^{- 10}$
2. $A > B > C$
3. $C > B > A$
4. $A > C > B$
For the electro-chemical cell,
$M | M^{+} | | X^{-} | X, E^{0} (M^{+} / M) = 0.44 V a n d E^{0} (X / X^{-}) = 0.33 V .$ From this data one can deduce that
1. $M + X \to M^{+} + X^{-}$ is the spontaneous reaction
2. $M^{+} + X^{-} \to M + X$ is the spontaneous reaction
3. $E_{c e l l}$ = 0.77 V
4. $E_{c e l l}$ = - 0.77 V
$C u^{+}$ ion is not stable in aqueous solution because of disproportionation reaction. $E^{0}$ value for disproportionation of $C u^{+}$ is
$(G i v e n E_{C u^{2 + / C u^{+}}}^{0} = 0.34 V)$
1. - 0.49 V
2. 0.49 V
3. - 0.38 V
4. 0.38 V
In a cell that utilises the reaction $Z n (s) + 2 H^{+} (a q) \to Z n^{2 +} (a q) + H_{2} (g) a d d i t i o n o f H_{2} S O_{4}$ to cathode compartment will
1. Increase the E and shift equilibrium to the right
2. Lower the E and shift equilibrium to the right
3. Lower the E and shift equilibrium to the left
4. Increase the E and shift equilibrium to the left
The standard e.m.f. of a cell, involving one electron change is found to be 0.591 V at $25 ° C$ . The equilibrium constant of the reaction is $(F = 96, 500 C m o l^{- 1}; R = 8.314 J K^{- 1} m o l^{- 1})$
1. $1.0 \times 10^{10}$
2. 1.5875 g
3. 4825 g
4. 96500 g
The mass of copper deposited from a solution of $C u S O_{4}$ by passage of 5 A current for 965 second is
(Mol. wt. of copper = 63.5)
1. 15.875 g
2. 1.5875 g
3. 4825 g
4. 96500 g
A solution of a salt of a metal was electrolysed for 150 minutes with a currentg of 0.15 amperers. The weight of metal deposited was 0.783 g. The equivalent weight of the metal is
1. 55.97 g
2. 65.97 g
3. 75.97 g
4. 85.97 g
The resistance of 0.01 N NaCl solution at $25 ° C i s 200 Ω .$ Cell constant of conductivity cell is $1 c m^{- 1}$ . The equivalent conductance is
1. $5 \times 10^{2} Ω^{- 1} c m^{2} e q^{- 1}$
2. $6 \times 10^{3} Ω^{- 1} c m^{2} e q^{- 1}$
3. $7 \times 10^{4} Ω^{- 1} c m^{2} e q^{- 1}$
4. $8 \times 10^{5} Ω^{- 1} c m^{2} e q^{- 1}$
Which one of the following metals could not be obtained on electrolysis of aqueous solution of its salts ?
1. Ag
2. Mg
3. Cu
4. Cr
When the sample of copper with zinc impurity is to be purified by electrolysis, the appropriate electrodes are
1. Pure Zinc (Cathode)
  Pure Copper (Anode)
2. Mg
3. Cu
4. Cr
In the electrolytic cell, flow of electrons is from
1. Cathode to anode in solution
2. Cathode to anode through external supply
3. Cathode to anode through internal supply
4. Anode to Cathode through internal supply
A solution of sodium sulphate in water is electrolysed using inert electrodes. The products at the cathode and anode are respectively
1. $H_{2}, O_{2}$
2. $O_{2}, H_{2}$
3. $O_{2}, N a$
4. $O_{2}, S O_{2}$
Which of the following liberate hydrogen on reaction with dilute $H_{2} S O_{4}$ ?
1. Fe
2. Cu
3. Al
4. Hg
During electrolysis of a solution of $A g N O_{3}$ , 9650 couloms of charge passes through the electro-plating bath, the mass of silver deposited in the cathode will be
1. 1.08 g
2. 10.8 g
3. 21.6 g
4. 108 g
ASSERTION : For a cell reaction $Z n (s) + C u^{2 +} (a q) \to Z n^{2 +} (a q) + C u (s);$ at the equilibrium, voltmeter gives zero reading.
REASON : At the equilibrium, there is no change in the concentration of $C u^{2 +} a n d Z n^{2 +}$ .
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : The resistivity for a substance is its resistance when it is one meter long and its area of cross section is one square meter.
REASON : The SI units of resistivity are ohm meter $(Ω m)$ and ohm centimeter $(Ω c m)$ .
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : $N i / N i^{2 +} (1.0 M) | | A u^{3 +} (1.0 M) | A u, f o r t h i s e l l e m f i s 1.75 V i f {E^{0}}_{A u^{3 + / A u}} = 1.50 a n d {E^{0}}_{N i^{2 + / N i}} = 0.25 V .$
REASON : Emf of the cell = ${E^{0}}_{c a t h o d e} - {E^{0}}_{a n o d e} .$
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : $E^{0} f o r M n^{3 +} / M n^{2 +}$ is more positive than $C r^{3 +} / C r^{2 +}$ .
REASON : The third ionization energy of Mn is larger than that of Cr.
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : Molar conductivity of a weak electrolyte at infinite dilution cannot be determined experimentally.
REASON : Kohlrausch's law help to find the molar conductivity of a weak electrolyte at infinite dilution.
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : Molar conductivity increased with decreases in concentration for weak electrolytes.
REASON : Number of ions per unit volume decreased due to dilution.
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : Conductivity always decreases with the decreased in concentration of both the weak and strong electrolytes.
REASON : Number of ions per unit volume linearly decreases in both electrolytes.
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : The cell potential of mercury cell is 1.35 V, which remains constant.
REASON : In mercury cell, the electrolyte is a paste of KOH and ZnO.
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : Copper reacts with hydrochloric acid and liberates hydrogen from the solution of dilute hydrochloric acid.
REASON : Hydrogen is below copper in the electro-chemical series.
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : Specific conductivity of an electrolytic solution decreases with dilutiom, whereas molar conductivity increases with dilution.
REASON : Specific conductivity is the conductance of a specific amount of the electrolyte, whereas molar conductivity is for 1 mole of the electrolyte.
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : The cell constant of a conductivity cell depends upon the nature of the material of the electrodes.
REASON : The electrodes of the cell are coated with platinum black to avoid polarization effects.
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : When acidified zinc sulphate solution is electrolysed between zinc electrodes, it is zinc that is deposited at the cathode and no $H_{2}$ gas is evolved.
REASON : The electrode potential of zinc is more negative than that of hydrogen as the over-voltage for the $H_{2}$ evolution on zinc is quite large.
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : Electrolysis of an aqueous solution of KI gives $I_{2}$ at the anode but that of KF gives $O_{2}$ at the anode and not $F_{2}$ .
REASON : $F_{2}$ is more reactive than $I_{2}$ .
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : Molar conductance of an electrolyte increases with dilution.
REASON : Ions have faster in dilute solutions.
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : The electrolysis aqueous NaCl solution gives hydrogen at the cathode and chlorime at the anode.
REASON : Chlorime has higher oxidation potential than water.
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : When 2 faraday of electricity is passed through 0.1 M $H_{2} S O_{4} (a q),$ 11.2 litres $O_{2}$ evolved at STP.
REASON : Molar weight of oxygen is 32.
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : Gold chloride $(A u C l_{3})$ solution cannot be stored in a vessel made of copper, iron, nickel chromium, zinc or tin.
REASON : Gold is very precious metal.
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : Copper is dissolved at anode and deposited at cathode hen Cu electrodes are used and electrolyte is $1 M C u S O_{4} (a q)$ solution.
REASOPN : SOP of Cu is less than SOP of water and SRP of Cu is greater than SRP of water.
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : The cell potential of mercujry cell is 1.35 V which remains constant.
REASON : In mercury cell, the electrolyte is a paste of KOH and HgO.
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : On dilution, the equivalent as well molar conductivity of the solution increases.
REASON : With dilution, the number of current carrying particles per $c m^{3}$ increases.
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : The electrode potential of SHE is zero only at $25 ° C$ and not at other temperature.
REASON : SHE is a standard reference electrodes.
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : Absolute value of ${E^{0}}_{r e d}$ of an electrode cannot be determined.
REASON : Neither oxidation nor reduction can take place alone.
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : ${E^{0}}_{c e l l} = 0$ for a chloride ion concentration cell.
REASON : For this concentration where ${E^{0}}_{c e l l} = \frac{R T}{n F} I n \frac{{[C l^{-}]}_{L H S}}{{[C l^{-}]}_{R H S}}$ .
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : If ${(\frac{d E_{c e l l}}{d T})}_{p} > 0$ for a cell reaction then $∆ S$ is positive.
REASON : $∆ S$ = $n F T {(\frac{d E}{d T})}_{p}$
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
ASSERTION : If an aqueous solution of NaCl is electrolysed, the product obtained at the cathode is $H_{2}$ gas and not Na.
REASON : Gases are liberated faster than the metals during the electrolysis of an electrolyte.
1. If both the assertion and reason are true and reason is a true explanation of the assertion.
2. If both the assertion and reason are true but the reason is not the correct explanation of assertion.
3. If assertion is true but reason is false.
4. If assertion is false but reason is true.
A conductance cell when filled with 0.5 M KCl solution (conductivity = 6.67 x 10^-3 Ω^-1 cm^-1) registers a resistance of 243 Ω. Its cell constant is
1. 1.62 cm
2. 1.62 cm^-1
3. 1.62 dm^-1
4. 1.62 m^-1
Which of the following is not correct?
1. The metallic conduction is due to the movement of electrons in the metal
2. The electrolytic conduction is due to the movement of ions in the metal
3. The current carrying ions are not necessarily discharged at the electrodes
4. The metallic conduction increases with the increase in temperature, whereas that of electrolytic conduction decreases with temperature
The highest electrical conductivity of the following aqueous solution is of:
1. 0.1 M acetic acid
2. 0.1 M chloroacetic acid
3. 0.1 M fluoroacetic acid
4. 0.1 M difluoroacetic acid
Which of the following is correct?
1. Conductivity of a solution decreases with dilution,whereas molar conductivity increases with dilution
2. Conductivity of a solution increases with dilution,whereas molar conductivity decreases with dilution
3. Both Conductivity and molar conductivity decreases with dilution
4. Both Conductivity and molar conductivity increases with dilution
The equivalent conductance of an infinitely dilute solution of NH₄Cl is 150 and the ionic conductance of OH^- and Cl^- ions are 198 and 76 respectively. If the equivalent conductance of a 0.01 N solution of NH₄OH is 9.6. What will be its degree of dissociation?
1. 0.0353
2. 0.0103
3. 0.96
4. 0.414
1 mol each of AgNO₃, CuSO₄ and AlCL₃ is electrolysed. The number of faradays required is in the ratio of
1. 1 : 1 : 1
2. 1 : 2 : 3
3. 3 : 2 : 1
4. 1 : 3 : 1
Faradays law of of electrolysis are related to the
1. atomic number of the cation
2. charge on 6.24 x 10¹⁸ electrons
3. charge on 1 electron
4. none of the above
One coulomb is equal to
1. 96500
2. charge on 6.24 x 10¹⁸ electrons
3. charge on 1 electron
4. none of the above
Which of the following will not conduct electricity in aqueous solution?
1. Copper sulphate
2. Common salt
3. Sugar
4. None of these
Which one of the following metals could not be obtained on electrolysis of aqueous solution of its salts?
1. Ag
2. Cr
3. Cu
4. Mg
The amount of ion discharged during electrolysis is not directly proportional to
1. Current
2. Time
3. Resistance
4. Chemical equivalent of the ion
Electrolysis involves oxidation and reduction respectively at
1. Cathode and anode
2. Anode and cathode
3. At both the electrodes
4. None of the above
Which of the following is not a non-electrolyte?
1. Urea
2. Glucose
3. Ethanol
4. Acetic acid
Amount of the electricity that can deposit 108 g of silver from AgNO₃ solution is
1. 1 ampere
2. 1 faraday
3. 1 coulomb
4. None of these
The atomic weight of Al is 27. When a current of 5F is passed through a solution of Al⁺⁺⁺ ions, the weight of Al deposited is
1. 27 g
2. 36 g
3. 39 g
4. 45 g
A certain current liberated 0.504 g of hydrogen in 2 hours. How many grams of copper can be liberated by the same current flowing for the same time in a copper sulphate solution?
1. 12.7 g
2. 31.8 g
3. 15.9 g
4. 63.5 g
96500 ciulombs of elevctric current liberates from solution
1. 63.5 g Cu
2. 96500 g Cu
3. 31.75 g Cu
4. 100 g Cu
Charge required to liberate 11.5 g sodium is
1. 96500 C
2. 0.1 F
3. 1.5 F
4. 0.5 F
The amount of silver deposited by passing 241.25 C of current through silver nitrate solution is
1. 2.7 g
2. 2.7 mg
3. 0.54 g
4. 0.27 g
In electrolysis of dilute H₂SO₄ using platinum electrodes
1. Cl₂ is obtained at cathode
2. NH₃ is produced at anode
3. H₂ is evolved at cathode
4. O₂ is produced
In electrolysis of an aqueous solution of sodium sulphate, 2.4 L of oxygen at STP was liberated at anode. The volume of hydrogen at STP liberated at cathode would be
1. 1.2 L
2. 2.4 L
3. 2.6 L
4. 4.8 L
A current of strength 2.5 A was passed through CuSO₄ solution for 6 minutes 265 seconds. The amount of copper deposited is
1. 0.3175 g
2. 1.028 g
3. 0.514 g
4. 6.35 g
During discharge of a lead storage cell the density of sulphuric acid in the cell
1. Increasing
2. Decreasing
3. Remains changed
4. Initially increases but decreases subsequently
An example of a simple fuel cell is
1. Lead storage battery
2. H₂ - O₂ cell
3. Daniel Cell
4. Leclanche cell
When iron is rusted it is
1. reduced
2. oxidised
3. evaporated
4. decomposed
Which of the following would occur when lead storage cell is charged?
1. Sulphuric acid is consumed
2. Sulphuric acid is formed
3. lead sulphate is formed
4. lead is consumed
Which of the following statement is true for fuel cells?
1. They are more efficient
2. They are free from pollution
3. They run till reactants are active
4. All of these
Metals can be prevented from rusting by
1. Connecting iron to more electropositive metal cathodic protection
2. Connecting iron to more electropositive metal anodic protection
3. Connecting iron to less electropositive metal anodic protection
4. Connecting iron to less electropositive metal cathodic protection
A depolarizer used in dry cell batteries is
1. ammonium chloride
2. manganese dioxide
3. potassium hydroxide
4. sodium phosphate
In galvanic cell
1. Chemical reaction produces electrical energy
2. Electrical energy produces chemical reaction
3. Reduction occurs at anode
4. Oxidation occurs at cathode
The standard potentials at 25° C for the following half reactions are given against them
$Z n^{2 +} + 2 e^{-} \to Z n, E^{0} = - 0.762 V$
$M g^{2 +} + 2 e^{-} \to Z n, E^{0} = - 2.37 V$
When zinc dust is added to a solution of magnesium chloride
1. No reaction will take place
2. Zinc chloride is formed
3. Zinc dissolve in solution
4. Magnesium is precipated
Which of the following statement is correct?
1. In SHE, the pressure of dihydrogen gas should be low and pH of solution should be zero
2. In the reaction $H_{2} O_{2} + O_{3} \to 2 H_{2} O + 2 O_{2}, H_{2} O_{2}$ is oxidised to $H_{2} O$
3. The absolute value of electrodepotential cannot be determined
4. According to IUPAC conventions, the standard electrode potential pertains to oxidation reaction only
Two half cells have reduction potentials -0.76 V and -0.13 V respectively. A galvanic cell is made from these two half cells. Which of the following is statements is correct?
1. Electrode of half cell potential -0.76 V serve as cathode
2. Electrode of half cell potential -0.76 V serve as anode
3. Electrode of half cell potential -0.13 V serve as anode
4. Electrode of half cell potential -0.76 V serve as positive electrode and -0.13 V as negative electrode
If a spoon of copper metals is placed in a solution of ferrous sulphate
1. Cu will precipitate
2. Iron will precipitate
3. Cu and Fe will precipitate
4. No reaction will take place
If the half cell potential A + e^- $\to$ A^- has alarge negative reduction potential as follows that
1. A is readily reduced
2. A is readily oxidised
3. A^- is readily oxidised
4. A is readily oxidised
Four alkali metals P,Q, R, S are having respectively, standard electrode potential as -3.05, -1.66, -0.40, and 0.80 V. Which one will be the most reducing?
1. P
2. Q
3. R
4. S
The electrode potential becomes equal to standard electrode when reactants and products concentration ratio is
1. equal to 1
2. greater than 1
3. less than 1
4. none of these