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)
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Consider the change in oxidation state of Bromine corresponding to different emf values as shown in the diagram below:
Then the species undergoing disproportionation is:-
1. | \(\text{BrO}^-_3\) | 2. | \(\text{BrO}^-_4\) |
3. | \(\text{Br}_2\) | 4. | \(\text{HBrO}\) |
The pressure of H2 required to make the potential of H2 - electrode zero in pure water at 298 K is:
1. | 10–12 atm | 2. | 10–10 atm |
3. | 10–4 atm | 4. | 10–14 atm |
A device that converts the energy of combustion of fuels, like hydrogen and methane, directly into electrical energy is known as:
1. | Fuel cell. | 2. | Electrolytic cell. |
3. | Dynamo. | 4. | Ni-Cd cell. |
When 0.1 mol MnO42– is oxidized, 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
A hydrogen gas electrode is made by dipping platinum wire in a solution of HCl of pH = 10 and by passing hydrogen gas around the platinum wire at one atm pressure. The oxidation potential of the electrode would be:
1. | 0.59 V | 2. | 0.118 V |
3. | 1.18 V | 4. | 0.059 V |
Zn2+(aq) + 2e–→ Zn(s) | Eo = – 0.76 V |
Ag2O(s) + H2O(l) + 2e– → 2Ag(s) + 2OH–(aq) | Eo = 0.34 V |
The cell potential will be:
1. | 0.42 V | 2. | 0.84 V |
3. | 1.34 V | 4. | 1.10 V |
Limiting molar conductivity of NH4OH (i.e., is equal to -
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