A hydrogen gas electrode is made by dipping platinum wire in a solution of HCI of pH = 10 and by passing hydrogen gas around the platinum wire at 1 atm pressure. The oxidation potential of the electrode would be:
1. 0.059 V
2. 0.59 V
3. 00.118 V
4. 1.18 V
The atomic mass of Al is 27. When a current of 5 faraday is passed through a solution of Al3+ ions, the mass of Al deposited is:
1. 27 g
2. 36 g
3. 45 g
4. 9 g
On the basis of the information available from the reaction.
of O2, the minimum EMF required to carry out the electrolysis of Al2O3 is : (F=96500 C mol-1)
1. 2.14 V
2. 4.28 V
3. 6.42 V
4. 8.56 V
For the reductidon of silver ions with copper metal, the standard cell potential was found to be + 0.46 V at 250C. The value of standard Gibbs energy(G0) will be ;
(F = 96500 Cmol-1)
1. -89.0 KJ
2. -89.0 J
3. -44.5 KJ
4. -98.0 KJ
A solution of sodium sulphate in water is electrolysed using inert electrodes. The products at the cathode and anode are respectively:
1. H2, O2
2. O2, H2
3. O2, Na
4. O2, SO2
What happens to the voltage in a galvanic cell when the salt bridge is removed?
1. The voltage drops to zero.
2. The voltage remains the same.
3. The voltage gradually increases.
4. The voltage rapidly increases.
Two electrolytic cells, one containing acidified ferrous chloride and another acidified ferric chloride are connected in series. The ratio of iron deposited at cathodes in the two cells when electricity is passed through the cells will be:
1. 3:1
2. 2:1
3. 1:1
4. 3:2
For the cell, Ti|Ti+(0.001M)||Cu2+(0.1M)|Cu,Ecell at 25C is 0.83 V. Ecell can be increased:
1. By increasing [Cu2+]
2. By increasing [Ti+]
3. By decreasing [Cu2+]
4. None of these
A galvanic cell is composed of two hydrogen electrodes, one of which is a standard one. In which of the following solutions should the other electrode be immersed to get maximum e.m.f.?
1. 0.1 M HCl
2. 0.1 M CH3COOH
3. 0.1 M H3P
4. 0.1 M H2SO4
Standard reduction potentials at 25C of Li+/Li, Ba2+/Ba, Na+/Na and Mg2+/Mg are -3.05, -2.90, -2.71 and -2.37 V respectively. Which one of the following is the strongest oxidising agent ?
1. Mg2+
2. Ba2+
3. Na+
4. Li+