The number of electrons that have a total charge of 9650 coulombs is_______.

(a)

6.22 ×10²³

(b)

6.022 ×10²⁴

(c)

6.022 ×10²²

(d)

6.022 ×10⁻³⁴

Consider the following half cell reactions.
Mn²⁺ + 2e^- ➝ Mn E^o = -1.18V
Mn²⁺ ➝ Mn³⁺ + e^- E^o = -1.51V
The E^o for the reaction 3Mn²⁺➝ Mn + 2Mn³⁺, and the possibility of the forward reaction are respectively.

(a)

2.69V and spontaneous

(b)

-2.69 and non spontaneous

(c)

0.33V and Spontaneous

(d)

4.18V and non spontaneous

The button cell used is watches function as follows
Zn (s) + Ag₂O (s) + H₂O (l) ⇌ 2Ag (s) + Zn²⁺ (aq) + 2OH^-(aq) the half cell potentials are Ag₂O (s) + H₂O (l) + 2e^- → 2Ag (s) + 2OH^- (aq) E^o = 34V and Zn (s) → Zn²⁺ (aq) + 2e⁻ E⁰ = 0.76V . The cell potential will be_______.

(a)

0.84V

(b)

1.34V

(c)

1.10V

(d)

0.42V

The molar conductivity of a 0.5 mol dm^-3 solution of AgNO₃ with electrolytic conductivity of 5.76 ×10⁻³ S cm⁻¹at 298 K is______.

(a)

2.88 S cm²mol^-1

(b)

11.52 S cm²mol^-1

(c)

0.086 S cm²mol^-1

(d)

28.8 S cm²mol ^-1

Electrolyte	KCl	KNO3	HCl	NaOAC	NaCl
Λ- (Scm2 mol-1)	149.9	145.0	426.2	91.0	126.5

Calculate Λ^o_HoAC using appropriate molar conductances of the electrolytes listed above at infinite dilution in water at 25^oC_______.

(a)

517.2

(b)

552.7

(c)

390.7

(d)

217.5

Faraday constant is defined as_______.

(a)

charge carried by 1 electron

(b)

charge carried by one mole of electrons

(c)

charge required to deposit one mole of substance

(d)

charge carried by 6.22 ×10¹⁰ electrons

How many faradays of electricity are required for the following reaction to occur MnO₄^-→ Mn²⁺

(a)

5F

(b)

3F

(c)

1F

(d)

7F

A current strength of 3.86 A was passed through molten Calcium oxide for 41 minutes and 40 seconds. The mass of Calcium in grams deposited at the cathode is_______. (atomic mass of Ca is 40g / mol and 1F = 96500C).

(a)

4

(b)

2

(c)

8

(d)

6

During electrolysis of molten sodium chloride, the time required to produce 0.1mole of chlorine gas using a current of 3A is _____.

(a)

55 minutes

(b)

107.2 minutes

(c)

220 minutes

(d)

330 minutes

The number of electrons delivered at the cathode during electrolysis by a current of 1A in 60 seconds is ____. (charge of electron = 1.6 ×10⁻¹⁹C )

(a)

6.22 ×10²³

(b)

6.022 ×10²⁰

(c)

3.75 ×10²⁰

(d)

7.48 ×10²³

Which of the following electrolytic solution has the least specific conductance?

(a)

2N

(b)

0.002N

(c)

0.02N

(d)

0.2N

While charging lead storage battery _______.

(a)

PbSO₄ on cathode is reduced to Pb

(b)

PbSO₄ on anode is oxidised to PbO₂

(c)

PbSO₄ on anode is reduced to Pb

(d)

PbSO₄ on cathode is oxidised to Pb

Among the following cells
I) Leclanche cell
II) Nickel – Cadmium cell
III) Lead storage battery
IV) Mercury cell
Primary cells are ____.

(a)

I and IV

(b)

I and III

(c)

III and IV

(d)

II and III

Zinc can be coated on iron to produce galvanized iron but the reverse is not possible. It is because _______.

(a)

Zinc is lighter than iron

(b)

Zinc has lower melting point than iron

(c)

Zinc has lower negative electrode potential than iron

(d)

Zinc has higher negative electrode potential than iron

Assertion: pure iron when heated in dry air is converted with a layer of rust.
Reason: Rust has the composition Fe₃ O₄
Codes:
a) if both assertion and reason are true and reason is the correct explanation of assertion
b) if both assertion and reason are true but reason is not the correct explanation of assertion
c) assertion is true but reason is false
d) both assertion and reason are false

(a)

if both assertion and reason are true and reason is the correct explanation of assertion

(b)

if both assertion and reason are true but reason is not the correct explanation of assertion

(c)

assertion is true but reason is false

(d)

both assertion and reason are false

In H₂-O₂ fuel cell the reaction occur at cathode is _______.

(a)

O_2(g) + 2H₂O_(l) + 4e^- ⟶ 4OH⁻ _(aq)

(b)

H⁺(aq) + OH⁻ (aq) ⟶ H₂O (l)

(c)

2H₂ (g) + O₂ (g) ⟶ 2H₂O (g)

(d)

H⁺ + e^- ⟶ 1/2 H₂

The equivalent conductance of M/36 solution of a weak monobasic acid is 6 mho cm² equivalent^-1 and at infinite dilution is 400 mho cm² equivalent^-1. The dissociation constant of this acid is ______.

(a)

1.25 x 10⁻⁶

(b)

6.25 x 10^-6

(c)

1.25 x 10⁻⁴

(d)

6.25 x 10 ^-5

A conductivity cell has been calibrated with a 0.01M, 1:1 electrolytic solution (specific conductance (k = 1.25 x 10^-3cm^-1) in the cell and the measured resistance was 800 Ω at 25^oC. The cell constant is ______.

(a)

10⁻¹ cm⁻¹

(b)

10¹ cm⁻¹

(c)

1 cm⁻¹

(d)

5.7 x 10^-12

Conductivity of a saturated solution of a sparingly soluble salt AB (1:1 electrolyte) at 298K is 1.85 ×10⁻⁵ S m⁻¹. Solubility product of the salt AB at 298K (Λ^o_m)_AB = 14 ×10⁻³ S m² mol⁻¹.

(a)

5.7 x 10^-12

(b)

1.32 x 10⁻¹²

(c)

7.5 x 10⁻¹²

(d)

1.74 x 10^-12

In the electrochemical cell: Zn|ZnSO_{4 (0.01M)}|| CuSO_{4 (1.0M)}|Cu, the emf of this Daniel cell is E₁. When the concentration of ZnSO₄ is changed to 1.0M and that CuSO₄ changed to 0.01M, the emf changes to E₂. From the above, which one is the relationship between E₁ and E₂?

(a)

E₁ < E₂

(b)

E₁ > E₂

(c)

E₂ ≥ E₁

(d)

E₁ = E₂

Consider the change in oxidation state of Bromine corresponding to different emf values as shown in the diagram below:
\({ BrO }_{ 4 }^{ - }\overset { 1.82V }{ \longrightarrow } { BrO }_{ 3 }^{ - }\overset { 1.5V }{ \longrightarrow } HBrO\overset { 1.595v }{ \longrightarrow } { Br }_{ 2 }\overset { 1.0652V }{ \longrightarrow } Br^{ - }\)
Then the species undergoing disproportional is

(a)

Br₂

(b)

BrO₄^-

(c)

BrO^-₃

(d)

HBrO

For the cell reaction
2Fe³⁺(aq) + 2l⁻(aq) \(\rightarrow\)2Fe²⁺ (aq) + 1₂ (aq)
E^o_cell = 0.24V  = at 298K. The standard Gibbs energy (Δ, G^o) of the cell reactions is:

(a)

-46.32 KJ mol⁻¹

(b)

-23.16 KJ mol^-1

(c)

46.32 KJ mol⁻¹

(d)

23.16 KJ mol^-1

A certain current liberated 0.504gm 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 ______.

(a)

31.75

(b)

15.8

(c)

7.5

(d)

63.5

A gas X at 1 atm is bubbled through a solution containing a mixture of 1MY^- and 1MZ^- at 25^oC. If the reduction potential of Z>Y>X, then_____.

(a)

Y will oxidize X and not Z

(b)

Y will oxidize Z and not X

(c)

Y will oxidize both X and Z

(d)

Y will reduce both X and Z

Cell equation: A + 2B^- \(\rightarrow\)A²⁺+ 2B; A²⁺ + 2e^- \(\rightarrow\)A E^o = +0.34V and log₁₀ K = 15.6 at 300K for cell reactions find E^o for B⁺ + e⁻ \(\rightarrow\) B 

(a)

0.80

(b)

1.26

(c)

-0.54

(d)

-10.94