Electrochemistry · Question 17

The molar conductivity of 0.007 M acetic acid is 20 S cm2 mol-1. What is the dissociation constant of acetic acid? Choose the correct option. [ H+ = 350 S cm2 mol-1 CH3COO- = 50 S cm2 mol-1]

1. 2.50 10-5 mol L-1
2. 1.75 10-4 mol L-1
3. 2.50 10-4 mol L-1
4. 1.75 10-5 mol L-1

On electrolysis of dil. sulphuric acid using Platinum (Pt) electrode, the product obtained at anode will be :

1. Oxygen gas
2. H2S gas
3. SO2 gas
4. Hydrogen gas

The number of Faradays(F) required to produce 20 g of calcium from molten CaCl2 (Atomic mass of Ca = 40 g mol-1) is :

1. 2
2. 3
3. 4
4. 1

For a cell involving one electron E cell = 0.59 V at 298 K, the equilibrium constant for the cell reaction is : [Given that 2.303 RTF = 0.059 V at T = 298 K]

1. 1.0 1030
2. 1.0 1010
3. 1.0 102
4. 1.0 105

For the cell reaction 2Fe3+(aq) + 2I-(aq) 2Fe2+(aq) + I2(aq) E cell = 0.24 V at 298 K. The standard Gibbs energy ( r G ) of the cell reaction is : [Given that Faraday constant F = 96500 C mol-1]

1. 46.32 kJ mol-1
2. 23.16 kJ mol-1
3. -46.32 kJ mol-1
4. -23.16 kJ mol-1

In the electrochemical cell : Zn | ZnSO4 (0.01 M) || CuSO4 (1.0 M) | Cu, the emf of this Daniell cell is E1. When the concentration of ZnSO4 is changed to 1.0 M and that of CuSO4 changed to 0.01 M, the emf changes to E2. From the following, which one is the relationship between E1 and E2? (Given, 2.303RTF = 0.059)

1. E1 < E2
2. E1 > E2
3. E2 = 0 E1
4. E1 = E2

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