﻿ At 250 molar conductance of 0.1 molar aqueous solutions of ammon

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## Electrochemistry

#### Multiple Choice Questions

251.

Using the Gibbs energy change, ΔG0 = +63.3 KJ for the following reaction,
Ag2CO3 (s) r2Ag+ (aq) + CO32- (aq)
the Ksp of Ag2CO3 (s) in water at 250 C is (R= 8.314 JK-1 mol-1)

• 3.2 x 10-26

• 8.0 x 10-12

• 2.9 x 10-3

• 2.9 x 10-3

2251 Views

# 252.At 250 molar conductance of 0.1 molar aqueous solutions of ammonium hydroxide is 9.54 ohm-1 cm2 mol-1 and at infinite dilution, its molar conductance is 238 ohm-1 cm2 mol-1. The degree of ionisation of ammonium hydroxide at the same concentration and temperature is  2.080% 20.800% 4.008% 4.008%

C.

4.008%

Given molar conductance at 0.1 M concentration,
λc = 9.54 Ω-1 cm2 mol-1
Molar conductance at infinite dilution,

2130 Views

253.

A button cell used in watches functions as following

The cell potential will be

• 1.10 V

• 0.42 V

• 0.84 V

• 0.84 V

1471 Views

254.

Limiting molar conductivity  of NH4OH (i.e.,  is equal to

725 Views

255.

Standard reduction potentials of the half-reactions are given below.

F2 (g) +2e- → 2F- (aq) ;  Eo = +2.85 V
Cl2 (g) +2e- →2Cl- (aq) ; Eo = +1.36V
Br2 (l) +2e- → 2Br(aq) ; Eo = +1.06 V
I2 (s) +2e- →2I- (aq); Eo = +0.53 V

The strongest oxidising and reducing agents respectively are

• F2 and I-

• Br2 and Cl-

• Cl2 and Br-

• Cl2 and Br-

666 Views

256.

Molar conductivities (Λom) at infinite dilution of NaCl, HCl and CH3COONa are 126.4, 425.9 and 91.0 S Cm2 mol-1 respectively. Λom for CH3COOH will be

• 425.5 S cm2 mol-1

• 180.5 S cm2 mol-1

• 290.8 S cm2 mol-1

• 290.8 S cm2 mol-1

1612 Views

257.

The Gibb's energy for the decomposition of Al2O3 at 500o C is as follow
2/3 Al2O→ 4/3 Al + O2;
ΔrG = +960 kJ mol-1
The potential difference needed for the electrolytic reduction aluminium oxide (Al2O3) at 5000 C is at least

• 4.5 V

• 3.0 V

• 2.5 V

• 2.5 V

3145 Views

258.

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

• Y > X > Z

• Z> X> Y

• X > Y > Z

• X > Y > Z

412 Views

259.

If the Eocell for a given reaction has a negative value then which of the following gives the correct relationships for the values of ΔGo and Keq ?

• ΔGo < 0; Keq > 1

• ΔGo < 0; Keq < 1

• ΔGo > 0; Keq < 1

• ΔGo > 0; Keq < 1

1145 Views

260.

The electrode potentials for

Cu2+ (aq) + e- → Cu+ (aq) and Cu+ (aq) + e- →Cu (s)

are +0.15 V and +0.50V respectively. The value of  will be

• 0.325 V

• 0.650 V

• 0.150 V

• 0.150 V

442 Views