21.

Given the data at 25^oC,
Ag + I^- → Agl +e^-; Eo = 0.152 V
Ag → Ag⁺ + e^- ;Eo = -0.800 V
What is the value of log K_sp for Agl?
(2.303RT/F = 0.059 V)

• –8.12

• +8.612

• –37.83

• –37.83

Resistance of a conductivity cell filled with a solution of an electrolyte of concentration 0.1 M is 100 Ω. The conductivity of this solution is 1.29 Sm^–1. Resistance of the same cell when filled with 0.2 M of the same solution is 520 Ω.The molar conductivity of 0.02 M solution of the electrolyte will be

• 124 × 10^–4 Sm² mol^–1

• 1240 × 10^–4 Sm² mol^–1

• 1.24 × 10^–4 Sm² mol^–1

• 1.24 × 10^–4 Sm² mol^–1

The ionic mobility of alkali metal ions in aqueous solution is maximum for

• K⁺

• Rb⁺

• Li⁺

• Li⁺

If α is the degree of dissociation of Na₂SO₄, the vant Hoff’s factor (i) used for calculating the molecular mass is

• 1 + α

• 1 - α

• 1 +2α

• 1 +2α

The highest electrical conductivity of the following aqueous solutions is of

• 0.1 M acetic acid

• 0.1 M chloroacetic acid

• 0.1 M fluoroacetic acid

• 0.1 M fluoroacetic acid

Aluminium oxide may be electrolysed at 1000^o  C to furnish aluminium metal (Atomic mass = 27 amu; 1 Faraday = 96,500 Coulombs). The cathode reaction is

Al³⁺ +3e^- → Al^o
To prepare 5.12 kg of aluminium metal by this method would require

• 5.49 x 10⁷ C of electricity

• 1.83 x 10⁷ C of electricity

• 1.49x 10⁷ C of electricity

• 1.49x 10⁷ C of electricity

• 517.2

• 552.7

• 390.7

• 390.7

Calomel ₍Hg₂Cl2) on reaction with ammonium hydroxide gives

• HgNH₂Cl

• NH₂ – Hg – Hg – Cl

• Hg₂O

• Hg₂O

Which among the following factors is the most important in making fluorine the strongest oxidizing halogen?

• Electron affinity

• Bond dissociation energy

• Hydration enthalpy

• Hydration enthalpy

In hydrogen-oxygen fuel cell, combustion of hydrogen occurs to

• generate heat

• remove adsorbed oxygen from electrode surfaces

• produce high purity water

• produce high purity water