Assertion : Fe³⁺ can be used for coagulation of As₂S₃ sol.

Reason: Fe³⁺ reacts with As₂S₃ to give Fe₂S₃.

• If both assertion and reason are true and reason is the correct explanation of the assertion.

• If both assertion and reason are true but reason is not the correct explanation of the assertion.

• If assertion is true, but reason is false.

• Both assertion and reason are false statements.

Assertion : Galvanised iron does not rust.

Reason : Zinc has a more negative electrode potential than iron.

• 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.

If equilibrium constant for reaction 2AB A₂ + B₂ is 49, then the equilibrium constant for reaction

AB $\rightleftharpoons$ $\frac{1}{2}$A₂ + $\frac{1}{2}$B₂, will be;

• 7

• 280

• 49

• 0.01

The E° for half cells Fe/Fe²⁺ and Cu/Cu²⁺ are -0.44 V and +0.32 V respectively. Then :

• Cu²⁺ oxidises Fe

• Cu²⁺ oxidises Fe²⁺

• Cu oxidises Fe²⁺

• Cu reduces Fe²⁺

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

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