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Question Bank No: 1

1. The cell Pt, $H_{2} (1 atm) / H^{+} (pH = x) ∥$ calomel electrode has emf of 0.67 V at $25^{0} C .$ If reduction potential of calomel electrode is 0.28 V, the value of x will be

a)		6.6
b)		3.3
c)		13.2
d)		1.1

2. The standard reduction potentials of ${Cu}^{2 +} / Cu$ and ${Cu}^{2 +} / {Cu}^{+}$ are 0.337 and 0.153 respectively.The standard electrode potential of ${Cu}^{2 +} / Cu$ half cell will be approximately.

a)		0.184 V
b)		0.827V
c)		0.521V
d)		0.490V

3. A current of 2 amp passing for five hours through the molten tin salt deposits 22.2 g of tin.The oxidation state of tin in the salt is

a)		+ 4
b)		+3
c)		+2
d)		+1

4. The net charge on one gram-ion of $N^{3 -}$ has been calculated by a student as Y $\times 10^{6} C .$ The value of Yis

a)		0.288
b)		8.2
c)		6
d)		3.49

5. Cadmium amalgam is prepared using a mercury cathode.The electricity required to prepare 10% Cd-Hg amalgam on a cathode of 3 g of Hg is

a)		9650 C
b)		568.6 C
c)		484 C
d)		600 C

6. An electrolytic cell contains a solution of ${Ag}_{2} {SO}_{4}$ and has Pt electrodes. Acurrent is passed till 1.6g of $O_{2}$ has been liberated at anode.The amount of silver deposited at cathode will be

a)		107.88g
b)		1.6g
c)		0.8g
d)		21.60g

7. In a solution of ${CuSO}_{4}$ how much time will be required to precipitate 2g copper by 0.5 ampere current?

a)		12157.48 sec
b)		102 sec
c)		510 sec
d)		642 sec

8. When the electricity is passed through aqueous solution of aluminium chloride,13.5g of Al are deposited .The number of Faradays of electricity passed must be

a)		2.0
b)		1.5
c)		1.0
d)		0.5

9. For the cell reaction to be spontaneous

a)		$E^{0} {}_{cell}> 0$
b)		$E^{0} {}_{cell}< 0$
c)		$Δ G > 0$
d)		$Δ G = 0$

10. The molar ionic conductance at infinite dilution of ${Ag}^{+}$ is 61.92 $\times 10^{- 4} S {mol}^{- 1} m^{2}$ at $25^{0} C .$ The ionic mobility of ${Ag}^{+}$ will be

a)		6.4 $\times 10^{- 4}$
b)		6.192
c)		6.192 $\times 10^{- 4}$
d)		3.2 $\times 10^{- 4}$

11. In SHE, the pH of the acid solution should be

a)		7
b)		14
c)		0
d)		4

12. The resistance of 0.0025 M solution of $K_{2} {SO}_{4}$ is 326 ohm.The specific conductance of the solution is

a)		4.997 $\times 10^{- 4}$
b)		5.997 $\times 10^{- 7}$
c)		6.997 $\times 10^{- 4}$
d)		unpredictable

13. A bulb draws a current of 4.0 ampere, the change in coulombs used by the bulb is 30 second is

a)		60C
b)		120C
c)		15C
d)		7.5C

14. During the elecrolysis of water 4 mol of electrons were transferred from anode to cathode.The total volume of the gases produced at STP will be approximately

a)		67.2L
b)		22.4L
c)		44.8L
d)		89.4L

15. The number of moles of KMnO4 required to oxidize one mole of ferrous oxalate in acidic medium is

a)		0.6
b)		0.4
c)		0.2
d)		1.67

16. The unit of molar conductivity is

a)		$Ω^{4} {cm}^{- 2} {mol}^{- 1}$
b)		$Ω {cm}^{- 2} {mol}^{- 1}$
c)		$Ω^{4} {cm}^{2} {mol}^{- 1}$
d)		$Ω {cm}^{2} mol$

17. The molar conductivity is maximum for the solution of concentration

a)		0.001M
b)		0.005M
c)		0.002M
d)		0.004M

18. On passing 0.1 faraday of electricity through aluminium chloride,the amount of aluminium metal deposited on cathode is (Al=27)

a)		0.27g
b)		0.3g
c)		0.9g
d)		2.7g

19. The number of electrons to balance the following equation
${NO}_{3}^{-}$ + ${4 H}^{2} + e \to {2 H}_{2} O + NO$ is

a)		5
b)		4
c)		3
d)		2

20. The equivalent conductance of NaCl, HCl and $C_{2} H_{5} COONa$ at infinite dilution are 126.45, 426.16 and 91 ${ohm}^{- 1} {cm}^{2}$ respectively. The eq. conductance of $C_{2} H_{5} COOH$ is

a)		201.28 ${ohm}^{- 1} {cm}^{2}$
b)		390.71 ${ohm}^{- 1} {cm}^{2}$
c)		698.28 ohm ${cm}^{2}$
d)		540.48 ohm ${cm}^{2}$

21. In the reaction ${Cu (s) + Ag}^{+} (aq) \to {Cu}^{2 +} (aq) + 2 Ag (s)$ , the reduction half cell reaction is

a)		${Cu + 2 e}^{-} \to {Cu}^{2 +}$
b)		${Cu - 2 e}^{-} \to {Cu}^{2 +}$
c)		${Ag}^{+} + e^{-} \to Ag$
d)		${Ag - 1 e}^{-} \to {Ag}^{+}$

22. Reaction that takes place at graphite anode in dry cell is

a)		${Zn}^{2 +} + 2 e^{-} \to Zn (s)$
b)		${Zn (s) \to Zn}^{2 +} + 2 e^{-}$
c)		${Mn}^{2 +} + 2 e^{-} \to Mn (s)$
d)		$Mn (s) \to {Mn}^{+} + e^{-} + 1.5 V$

23. An unknown metal M displaces nickel from nickel(II) sulphate solution but does not displace manganese from manganese sulphate solution. Which order represents the correct order of reducing power?

a)		Mn > Ni > M
b)		Ni > Mn > M
c)		Mn > M > Ni
d)		M > Ni > Mn

24. In the cell, $Zn | {Zn}^{2 +} | | {Cu}^{2 +} | Cu$ , the negative terminal is

a)		Cu
b)		${Cu}^{2 +}$
c)		Zn
d)		${Zn}^{2 +}$

25. The resistance of 1N solution of acetic acid is 250 ohm, when measured in a cell of cell constant 1.15 ${cm}^{- 1}$ . The equivalent conductance (in ${ohm}^{- 1} {cm}^{2} {equiv}^{- 1}$ ) of 1N acetic acid is

a)		4.6
b)		9.2
c)		18.4
d)		0.023

26. Which of the following is a strong electrolyte?

a)		${{Ca (NO}_{3})}_{2}$
b)		HCN
c)		${CH}_{3} COOH$
d)		${NH}_{4} OH$

27. The standard ${E^{\circ}}_{Red}$ values of A, B, C are 0.68V, -2.54V, -0.50V respectively. The order of their reducing power is

a)		A > B > C
b)		A > C > B
c)		C > B > A
d)		B > C > A

28. The conductivity of strong electrolyte

a)		increases on dilution slightly
b)		does not change on dilution
c)		decreases on dilution
d)		depends on density of electrolyte it self

29. A certain current liberate 0.5 g of hydrogen in 2 h. How many grams of copper can be liberated by the same current flowing for the same time in a copper sulphate solution?

a)		12.7 gm
b)		15.9 gm
c)		31.8 gm
d)		63.5 gm

30. If half cell reaction A+ $e^{-} \to A^{-}$ has a large negative reduction potential, it follows that

a)		A is readily reduced
b)		A is readily oxidized
c)		$A^{-}$ readily reduced
d)		$A^{-}$ is readily oxidized

31. The name associated with equation E = $E^{\circ} + \frac{RT}{nF} l n \frac{[M^{n +}]}{[M]}$ is

a)		van der Waal equation
b)		Berthelot equation
c)		Nernst equation
d)		Diterici equation

32. Electrolytes when dissolved in water dissociate into ions because

a)		they are unstable
b)		the water dissolves it
c)		the forces of repulsion increase
d)		the forces of electrostatic attraction are broken down by water

33. When electricity is passed through a solution of ${AlCl}_{3}$ and 13.5 gms of Al are deposited, the number of faraday must be

a)		0.5
b)		1.0
c)		1.5
d)		2.0

34. Stronger the oxidising agent, greater is the

a)		Reduction potential
b)		Oxidation potential
c)		Ionic behaviour
d)		none of the above

35. When quantity of electricity passed is one faraday then the mass deposited at the electrode is equal to

a)		one gm. atomic weight
b)		one gm. equivalent weight
c)		electrochemical equivalent
d)		none of the above

36. In an experiment set up for the measurement of e.m.f. of a half- cell using a reference electrode and a salt bridge, when the salt bridge is removed the voltage

a)		does not change
b)		increases to maximum
c)		decreases to half the volume
d)		drops to zero

37. The position of some metals in the electrochemical series in decreasing electropositive character is given Mg > Al > Zn > Cu > Ag. What will happen if a copper spoon is used to stir a solution of aluminium nitrate?

a)		The spoon will get coated with aluminium
b)		An alloy of copper and aluminium is formed
c)		The solution becomes blue
d)		There is no reaction

38. On electrolysing a solution of dilute $H_{2} {SO}_{4}$ between platinum electrodes, the gas evolved at the anode is

a)		${SO}_{2}$
b)		${SO}_{3}$
c)		$O_{2}$
d)		$H_{2}$

39. Which of the following reactions actually take place?

a)		Zn(s) + ${2 Ag}^{+} (aq) \to$ ${Zn}^{+ +} + 2 Ag (s)$
b)		${Zn}^{+ +} + 2 Ag (s) \to 2 {Ag}^{+} (s) + Zn (s)$
c)		${Zn (s) + Ag (s) \to Zn}^{+ +} (aq) + {Ag}^{+} (aq)$
d)		${Zn}^{+ +} (aq) + {Ag}^{+} (aq)$ $\to Zn (s) + Ag (s)$