When aqueous NaCl solution is electrolysed using inert electrodes then pH of the solution-
1. Increases.
2. Decreases.
3. Remains same.
4. First increases then decreases.
In the electrochemical cell:
Zn|ZnSO4(0.01 M) || CuSO4(1.0M),Cu, the emf of this Daniel cell is E1. When the concentration of ZnSO4 is changed to 1.0 M and that of CuSO4 is changed to 0.01 M, the emf changes to E2. The relationship between E1 and E2 is :
( Given, = 0.059)
1. E1 = E2
2. E1 < E2
3. E1 > E2
4. E2 = 0 E1
The weight of silver (atomic weight = 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
The equilibrium constant of the reaction:
Cu (s) + 2Ag+ (aq) Cu2+ (aq) + 2Ag(s) ;
Eo = 0.46 V at 298 K is:
1. | 2.4 x 1010 | 2. | 2.0 x 1010 |
3. | 4.0 x 1010 | 4. | 4.0 x 1015 |
The quantity of electricity required to reduce 12.3 g of nitrobenzene to aniline with 50 % current efficiency is:
1. 1 F
2. 0.6 F
3. 0.5 F
4. 1.2 F
The maximum work which can be obtained from a Daniel cell \(Zn_{(s)}\ |\ Zn^{+2}_{(aq)}\ || Cu^{+2}_{(aq)}\ |\ Cu_{(s)}\) is:
\(E^o_{Zn^{2+}/Zn}\) | −0.76 V |
\(E^o_{Cu^{2+}/Cu}\) | 0.34 V |
1. 106.15 kJ
2. -212.3 kJ
3. 424.6 kJ
4. +212.3 kJ
At 298 K the Emf
of the following cell is:
\(\small{Pt|H_{2}(1 \ atm)|H^{+}(0.02 \ M) \ || \ H^{+}(0.01 \ M)|H_{2}(1 \ atm)|Pt}\)
1. - 0.017 V
2. 0.0295 V
3. 0.1 V
4. 0.059 V
By how much will the potential of half cell Cu2+| Cu change if the solution is diluted to 100 times at 298 K. It will -
1. | Increase by 59 mV | 2. | Decrease by 59 mV |
3. | Increase by 29.5 mV | 4. | Decrease by 29.5 mV |
During electrolysis of conc. H2SO4, perdisulphuric acid (H2S2O8), and O2 form in equimolar amount. The amount of H2 that will form simultaneously will be :
1. Thrice that of O2 in moles.
2. Twice that of O2 in moles.
3. Equal to that of O2 in moles.
4. Half of that of O2 in moles.
If a salt bridge is removed from the two half cells, the voltage:
1. Drops to zero.
2. Does not change.
3. Increases gradually.
4. Increases rapidly.