Multiple Choice QuestionsWhich of the following statements is true for the electrochemical Daniell cell?
Electrons flow from copper electrode to zinc electrode.
Current flows from zinc electrode to copper electrode.
Cations move toward copper electrode.
Cations move toward zinc electrode.
Assertion : Copper metal gets readily corroded is an acidic aqueous solution.
Reason : Free energy change for this process is positive.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false.
Which of the following reactions is used to make a fuel cell?
Cd(s) + 2Ni(OH)3 → CdO(s) + 2Ni(OH)2(s) + H2O(l)
Pb(s) + PbO2(s) + 2H2SO4(aq) → 2PbSO4(s) + 2H2O(l)
2H2(g) + O2(g) →6 2H2O(l)
2Fe(s) + O2(g) + 4H+ (aq) → 2Fe2+(aq) + 2H2O(l)
C.
2H2(g) + O2(g) →6 2H2O(l)
Fuel cells are galvanic cells in which chemical energy of fuels is directly converted into electrical energy. e.g., Hydrogen- oxygen fuel cell. The reaction is-
2H2(g) + O2(g) →6 2H2O(l)
Time required to deposit one millimole of aluminium metal by the passage of 9.65 amperes through aqueous solution of aluminium ion is
30 s
10 s
30,000 s
10,000 s
How many electrons are de! ivered at the cathode during electrolysis by a current of 1 A in 60 seconds?
3.74 x 1020
6.0 x 1023
7.48 x 1021
6.0 x 1020
At a particular temperature, the ratio of equivalent conductance to specific conductance of a 0.01 N NaCl solution is
105 cm3
103 cm3
10 cm3
105 cm2
The number of moles of electrons required to deposit 1gm equivalent aluminium (atomic wt. = 27) from a solution of aluminium chloride will be
3
1
4
2
At temperature of 298K, the emf of the following electrochemical cell,
Ag (s) | Ag+ (0.1 M)|| Zn2+ (0.1 M) | Zn (s) will be (Given, E°cell = -1.562 V)
-1.532 V
-1.503 V
1.532 V
-3.06 V
Assertion: Potassium and caesium are used in photoelectric cells.
Reason: Potassium and caesium emit electrons on exposure to light.
If both assertion and reason are true and reason is a correct explanation of the assertion.
If both the assertion and reason are true but the reason is not a correct explanation of the assertion.
If the assertion is true but the reason is false.
If both the assertion and reason are false.
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