Corrosion of iron is essentially an electrochemical phenomenon where the cell reactions are

• Fe is oxidised to Fe²⁺ and dissolved oxygen in water is reduced to OH^-.

• Fe is oxidised to Fe³⁺ and H₂O is reduced to O${}_2^{2-}$.

• Fe is oxidised to Fe²⁺ and H₂O is reduced to O${}_2^{-}$.

• Fe is oxidised to Fe²⁺ and H₂O is reduced to O₂.

522.

The standard electrode potential is measured by

• electrometer

• voltmeter

• pyrometer

• galvanometer

When a quantity of electricity is passed through CuSO₄ solution, 0.16 g of copper gets deposited. If the same quantity of electricity is passed through acidulated water, then the volume of H₂ liberated at STP will be : [given : atomic weight of Cu = 64]

• 4.0 cm³

• 56 cm³

• 604 cm³

• 8.0 cm³

Which one of the following condition will increase the voltage of the cell represented by the equation?

Cu(s) + 2Ag⁺(aq) $\rightleftharpoons$Cu²⁺(aq) + 2Ag(s)

• Increase inthe dimension of Cu electrode

• Increase in the dimension of Ag electrode

• Increase inthe concentration of Cu²⁺ ion.

• Increase in the concentration of Ag⁺ ions.

Which of the following electrolytic solutions has the least specific conductance?

• 0.02N

• 0.2 N

• 2 N

• 0.002 N

Hydrogen gas is not liberated when the following metal is added to dil HCl

• Ag

• Zn

• Mg

• Sn

The standard electrode potential for the half-cell reactions are

Zn²⁺ + 2e^- → Zn; E° = -0.76 V

Fe²⁺ + 2e^- → Fe; E° = 0.44 V

The emf of the cell reaction, Fe²⁺ + Zn → Zn²⁺ + Fe is

• -0.32 V

• -1.20 V

• +1.20 V

• +0.32 V

In the electrolysis of acidulated water, it is desired to obtain 1.12 cc of hydrogen per second under STP condition. The current to be passed is

• 1.93 A

• 9.65 A

• 19.3 A

• 0.965 A

The one which decreases with dilution is

• molar conductance

• conductance

• specific conductance

• equivalent conductance

9.65 C of electric current is passed through fused anhydrous magnesium chloride. The magnesium metal thus, obtained is completely converted into a Grignard reagent. The number of moles of the Grignard reagent obtained is

• 5 × 10^-4

• 1 × 10^-4

• 5 × 10^-5

• 1 × 10^-5