Electrochemistry

The pressure of H2 required to make the potential of H2-electrode zero in pure water at 298 K is

1. 10-10 atm
2. 10-4 atm
3. 10-14 atm
4. 10-12 atm

The molar conductivity of a 0.5 mol/dm3 solution of AgNO3 with electrolytic conductivity of 5.76 10-3 S cm-1 at 298 K is

1. 2.88 S cm2/mol
2. 11.52 S cm2/mol
3. 0.086 S cm2/mol
4. 28.8 S cm2/mol

During the electrolysis of molten sodium chloride, the time required to produce 0.10 mol of chlorine gas using a current of 3 amperes is

1. 55 minutes
2. 110 minutes
3. 220 minutes
4. 330 minutes

If the E cell for a given reaction has a negative value, which of the following gives the correct relationships for the values of G and Keq ?

1. G > 0; Keq < 1
2. G > 0; Keq > 1
3. G < 0; Keq > 1
4. G < 0; Keq < 1

The number of electrons delivered at the cathode during electrolysis by a current of 1 ampere in 60 seconds is (charge on electron = 1.60 10-19 C)

1. 6 1023
2. 6 1020
3. 3.75 1020
4. 7.48 1023

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

1. zinc is lighter than iron
2. zinc has lower melting point than iron
3. zinc has lower negative electrode potential than iron
4. zinc has higher negative electrode potential than iron

Aqueous solution of which of the following compounds is the best conductor of electric current ?

1. Hydrochloric acid, HCl
2. Ammonia, NH3
3. Fructose, C6H12O6
4. Acetic acid, C2H4O2

A device that converts energy of combustion of fuels like hydrogen and methane, directly into electrical energy is known as

1. dynamo
2. Ni-Cd cell
3. fuel cell
4. electrolytic cell

When 0.1 mol MnO42- is oxidised the quantity of electricity required to completely oxidise MnO42- to MnO4- is

1. 96500 C
2. 2 96500 C
3. 9650 C
4. 96.50 C

The weight of silver (at. wt. = 108) displaced by a quantity of electricity which displaces 5600 mL of O2 at STP will be

1. 5.4 g
2. 10.8 g
3. 54.0 g
4. 108.0 g