General
✓✗The emf of a galvanic cell changes when
- the concentrations of the ions are changed
- the volume of each solution is doubled at the same concentration
- the size of the electrodes is changed
- the length of the salt bridge is changed
General
✓✗The value of the Faraday constant is approximately
- 96500 C mol−1
- 6.022 × 1023 C mol−1
- 1.6 × 10−19 C mol−1
- 9650 C mol−1
General
✓✗A solution contains Fe2+, Fe3+ and I− ions. This solution was treated with iodine at 35 °C. E° for Fe3+/Fe2+ is +0.77 V and E° for I2/2I− is 0.536 V. The favourable redox reaction is
- there will be no redox reaction
- I− will be oxidised to I2
- I2 will be reduced to I−
- Fe2+ will be oxidised to Fe3+
General
✓✗How many grams of cobalt metal will be deposited when a solution of cobalt(II) chloride is electrolysed with a current of 10 amperes for 109 minutes? (1 F = 96500 C; atomic mass of Co = 59 u)
- 0.66
- 4.0
- 20.0
- 40.0
General
✓✗The cathode reaction in a dry (Leclanché) cell is
- Ag2O + H2O + 2e− → 2Ag + 2OH−
- Zn → Zn2+ + 2e−
- 2H+ + 2e− → H2
- MnO2 + NH4+ + e− → MnO(OH) + NH3
General
✓✗The correct value of cell potential (in volt) for the reaction that occurs when the following two half-cells are connected is
Fe2+(aq) + 2e− → Fe(s), E° = −0.44 V
Cr2O72−(aq) + 14H+ + 6e− → 2Cr3+ + 7H2O, E° = +1.33 V
Fe2+(aq) + 2e− → Fe(s), E° = −0.44 V
Cr2O72−(aq) + 14H+ + 6e− → 2Cr3+ + 7H2O, E° = +1.33 V
- +0.01 V
- +0.89 V
- +2.65 V
- +1.77 V
General
✓✗Assertion: Zinc displaces copper from copper sulphate solution.
Reason: The standard reduction potential of zinc is less than that of copper.
Reason: The standard reduction potential of zinc is less than that of copper.
- Both Assertion and Reason are true and Reason is the correct explanation of Assertion
- Both Assertion and Reason are true but Reason is not the correct explanation of Assertion
- Assertion is true but Reason is false
- Both Assertion and Reason are false
General
✓✗Given E°(MnO4−/MnO2) = 1.70 V and E°(MnO2/Mn2+) = 1.23 V, the value of E°(MnO4−/Mn2+) is
- 1.512 V
- 2.930 V
- 1.418 V
- 1.465 V
General
✓✗For a strong electrolyte Λm = Λm° − A√c. If Λm = 124.0 at c = 0.01 M and Λm = 120.0 at c = 0.04 M (S cm2 mol−1), Λm° is
- 126.0 S cm2 mol−1
- 130.0 S cm2 mol−1
- 128.0 S cm2 mol−1
- 132.0 S cm2 mol−1
General
✓✗If ΔG° for a cell reaction is negative, the cell reaction is
- non-spontaneous
- impossible
- spontaneous
- at equilibrium
General
✓✗The current required to deposit 0.54 g of Al in 5 minutes from molten alumina is (Al = 27 g mol−1)
- 9.7 A
- 6.4 A
- 19.3 A
- 1158.0 A
General
✓✗The emf of the cell Pt|H2(10 bar)|H+(1 M)||H+(1 M)|H2(1 bar)|Pt at 298 K is
- 0.0000 V
- 0.0590 V
- −0.0295 V
- 0.0295 V
General
✓✗In a galvanic cell, electrons flow in the external circuit from
- the salt bridge to the anode
- cathode to salt bridge
- cathode to anode
- anode to cathode
General
✓✗The SI unit of conductance is
- ohm
- S m2 mol−1
- S m−1
- siemens (S)
General
✓✗The standard reduction potentials of Cu2+/Cu and Ag+/Ag are 0.34 V and 0.80 V. For the cell Cu|Cu2+(0.01 M)||Ag+(x M)|Ag, the emf at 298 K is 0.46 V. The value of x is
- 1.000 M
- 0.100 M
- 0.001 M
- 0.010 M