An aqueous solution containing 6.5 g of NaCl of 90 purity was subjected to electrolysis. After the complete electrolysis, the solution was evaporated to get solid NaOH. The volume of 1 M acetic acid required to neutralise NaOH obtained above is :

• 1000 cm³

• 2000 cm³

• 100 cm³

• 200 cm³

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 ${\mathrm{O}}_2^{2-}$

• Fe is oxidised to Fe²⁺ and H₂O is reduced to ${\mathrm{O}}_2^{2-}$

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

On the basis of standard electrode potential of redox couples given below, find out which of the following is the strongest oxidising agent.

(E$°$ values : Fe³⁺ | Fe²⁺ = +0.77 V; I_2(s) | I^- = +0.54 V; Cu²⁺ | Cu = +0.34 V; Ag⁺ | Ag = +0.80 V)

• Fe³⁺

• I_2(s)

• Cu²⁺

• Ag⁺

Assertion : If standard reduction potential for the reaction Ag⁺ + e^- $\to$ Ag is 0.80 volt, then for the reaction 2Ag⁺ + 2e^- $\to$ 2Ag, it will be 1.60 volt.

Reason: If concentration of Ag⁺ ions is doubled, the standard electrode potential is also doubled.

• 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.

325.

How many Faradays of electricity are required for the given reaction to occur ?

Mn${\mathrm{O}}_4^{-} \to$Mn²⁺

• 5 F

• 3 F

• 1 F

• 7 F

A conductivity cell has a cell constant of 0.5 cm^-1. This cell when filled with 0.01 M NaCl solution has a resistance of 384 ohms at 25°C. Calculate the equivalent conductance of the given solution.

• 130.2 ${\Omega }^{-1}$ cm² (g eq)^-1

• 137.4 ${\Omega }^{-1}$ cm² (g eq)^-1

• 154.6 ${\Omega }^{-1}$ cm² (g eq)^-1

• 169.2 ${\Omega }^{-1}$ cm² (g eq)^-1

Ionic conductances of H⁺ and S${\mathrm{O}}_4^{2-}$ at infinite dilution are x and y S cm² equiv^-1 . Hence , equivalent conductance of H₂SO₄ at infinite dilution is :

• (x + y)

• 2(x + y)

• 2x + y

• x + 2y

In the refining ofsilver by electrolytic method, what will be the weight of 100 g Ag anode if 5A current is passed for hours ? The purity of silver anode is 95% by weight.

• 42.91 g

• 57.59 g

• 13.16 g

• 36.38 g

Salt bridge contains :

• calomel

• corrosive sublimate

• agar-agar paste

• H₂O

Assertion : In electrolysis, the quantity of electricity needed for depositing 1 mole of silver is different from that required for 1 mole of copper.

Reason : The molecular weights of silver and copper are different.

• 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