Assertion : Sodiumacetate on Kolbe's electrolysis gives methane.

Reason : Methyl free radical is formed at cathode.

• 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.

342.

Assertion : Magnesium is extracted by the electrolysis of fused mixture of MgCl₂, NaCl and CaCl₂.

Reason : Calcium chloride acts as a reducing agent.

• 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 a salt bridge is removed between the half cells , the voltage :

• decreases to zero

• increases

• increases rapidly

• do not change

During electrochemical process :

• Gibbs free energy increases

• Gibbs free energy remains constant

• no prediction can' be made about Gibbs free energy

• Gibbs free energy decreases

A factory produces 40 kg of calcium in two hours by electrolysis. How much aluminium can be produced by same current in 2 hours if current efficiency is 50%?

• 22 kg

• 18 kg

• 9 kg

• 27 kg

The standard emf of a cell , involving one electron change is found to be 0.591 V at 25^o C . The equilibrium constant of the reaction is :

(F = 96500 C mol^-1 , R = 8.314 JK^-1mol^-1)

• 1.0 x 10¹

• 1.0 x 10⁵

• 1.0 x 10¹⁰

• 1.0 x 10³⁰

A complex PtCl₄.5NH₃, shows a molar conductance of 402 ohm^-1 cm²mol^-1 in water and precipitates three moles ofAgCl with AgNO₃ solution. The formula of the complex is

• [Pt(NH₃)₆]Cl₄

• [Pt(NH₃)₄Cl₂]Cl₂

• [Pt(NH₃)₅Cl]Cl₃

• [Pt(NH₃)₃Cl₃]Cl

Calculate ${\wedge }_{\mathrm{HOAC}}^{\infty }$ using appropriate molar conductances of the electrolytes listed above at infinite dilution in H₂O at 25°C.

Electrolyte	KCl	KNO3	HCL	NaOAc	NaCl
$\frac{{\wedge }^{\infty }}{\mathrm{S} {\mathrm{cm}}^2{\mathrm{mol}}^{-1}}$	149.9	145.0	426.2	91.0	126.5

• 517.2

• 552.7

• 390.7

• 217.5

The standard half-cell reduction potential for Ag⁺| Ag is 0.7991 V at 25°C. Given the experimental value K_sp= 1.56 x 10^-10 for AgCl, calculate the standard half-cell reduction potential for the Ag | AgCl electrode.

• 0.2192V

• -0.2192V

• -1.2192 V

• 1.2192 V

Assertion : Reduction potential of Mn (+3 to +2) is more positive than Fe (+3 to +2).

Reason: Ionisation potential of Mn is more than that of Fe.

• 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.