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 |
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.
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.
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 discharge of a lead storage cell, the density of sulphuric acid in the cell-
1. Increases.
2. Decreases.
3. Remains unchanged.
4. Initially increases but decreases subsequently.