CBSE
Multiple Choice QuestionsStandard 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-
The pressure of H2 required to make the potential of H2-electrode zero in pure water at 298 K is
10-12 atm
10-10 atm
10-4 atm
10-4 atm
Limiting molar conductivity of NH4OH (i.e., 
is equal to
The Gibb's energy for the decomposition of Al2O3 at 500o C is as follow
2/3 Al2O3 → 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
A device that converts energy of combustion of fuels like hydrogen and methane, directly into electrical energy is known as
fuel cell
electrolytic cell
dynamo
dynamo
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
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
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%
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
When 0.1 mol MnO42- is oxidised, the quantity of electricity required to completely oxidise MnO42- to MnO42- is
95600C
2 x 96500C
9650 C
9650 C
