The time required to deposit one millimole of aluminium metal from Al2O3, by passing 9.65 amperes through solution of aluminium ion is
30 s
10 s
30,000 s
10,000 s
In a Daniell cell, the value of standard free energy (ΔGº) is -212.3 kJ at 25ºC. What will be the value of ln Kc?
65.7
85.7
171.7
343.7
The conductance of electrolytes increases with
increase in pressure
decrease in pressure
increase in temperature
decrease in temperature
The mass of copper deposited from a solution of Cu2S by passing a current of 2.5 ampere for 6 minute is
0.3 g
0.5 g
0.7 g
0.9 g
In the reaction : Ag2O + H2O2 → 2Ag + H2O + O2, the H2O2 acts as
reducing agent
oxidising agent
bleaching agent
none of these
The EoM3+/M2+ values for Cr, Mn, Fe and Co are -0.41 V, + 1.57 V, +0.77 V and +1.97 V respectively. For which one of the metals, the change in oxidation state from +2 to +3 will be easiest?
Cr
Co
Fe
Mn
The specific conductance of KCl solution at 23°C is 0.012 Ω-1 -cm-1. Resistance of cell containing the solution at same temperature was found to be 55 Ω. Cell constant will be
0.316 cm-1
0.616 cm-1
6.16 cm-1
616 cm-1
During the electrolysis of a solution of AgNO3, 9650 C of charge passes through the electroplating bath, the mass of silver deposited on the cathode will be
1.08 g
10.8 g
21.6 g
108 g
A galvanic cell prepared by combining Cu/Cu2+ and Al/Al2+ has an e.m.f. of 2.0 V at 298 K. If the potential of the copper electrode is +0.34V, then that of aluminium is
+1.66 V
-1.66 V
+ 2.34 V
-2.3 V
Which of the following reaction does not involve either in oxidation or reduction?
Cr → CrCl3
Na → Na+
2S2O32- → S4O62-
K2CrO4 → K2CrO7
