Which 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) + PbO_2(s) + 2H₂SO_4(aq) → 2PbSO_4(s) + 2H₂O_(l)

• 2H_2(g) + O_2(g) →6 2H₂O_(l)

• 2Fe_(s) + O_2(g) + 4H⁺ _(aq) → 2Fe²⁺_(aq) + 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

385.

A spoon to be electroplated with gold should be

• cathode

• anode

• electrolyte

• none of these.

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.