Chemistry Class 12 NCERT Solutions: Chapter 3 Electrochemistry Part 2

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Q: 6. The cell in which the following reactions occurs:

Calculate the standard Gibbs energy and the equilibrium constant of the cell reaction.

Answer:

Here,

We know that:

Again,

Q: 7. Why does the conductivity of a solution decrease with dilution?

Answer:

The conductivity of a solution is the conductance of ions present in a unit volume of the solution. The number of ions (responsible for carrying current) decreases when the solution is diluted. As a result, the conductivity of a solution decreases with dilution.

Q: 8. Suggest a way to determine the value of water.

Answer:

Applying Kohlrausch's law of independent migration of ions, the value of water can be determined as follows:

Hence, by knowing the values of , and , the value of water can be determined.

Q: 9. The molar conductivity of Methanoic acid is .

Calculate its degree of dissociation and dissociation constant. Given

Answer:

Now, degree of dissociation:

Thus, dissociation constant:

Q: 10. If a current of ampere flows through a metallic wire for 2 hours, then how many electrons would flow through the wire?

Answer:

Thus,

We know that number of electrons.

Then,

number of electrons

Hence, number of electrons will flow through the wire.

Q: 11. Suggest a list of metals that are extracted electrolytically.

Answer:

Metals that are on the top of the reactivity series such as sodium, potassium, calcium, lithium, magnesium, aluminium are extracted electrolytically.