Question

The amount of electricity that can deposit 108g of silver from ${\mathrm{AgNO}}_3$ solution is?

Answer 1

Step 1: Faraday's law:

• "The second law of Faraday’s law of electrolysis, states that “the charge of one mole of electrons is equal to one Faraday”.
• It can also be stated that “one Faraday of charge is required to form a one-gram equivalent of an element.”

Step 2: Reaction to the change in charge:

• The reaction to the change in charge can be depicted as:
• ${\mathrm{Ag}}^{+}\left(\mathrm{aq}\right)+{\mathrm{e}}^{-}\to \mathrm{Ag}\left(\mathrm{s}\right)$

Step 3: Calculation for equivalent weight:

• The gram equivalent can be represented as:
• $\mathrm{Gram}\mathrm{equivalent}=\frac{\mathrm{Given}\mathrm{mass}}{\mathrm{Equivalent}\mathrm{weight}}$
• And, $\mathrm{Equivalent}\mathrm{weight}=\frac{\mathrm{Molecular}\mathrm{mass}}{\mathrm{n}-\mathrm{factor}}$
• The molecular mass of silver is $108\mathrm{g}$ and the n-factor is one. Thus, the equivalent weight will be:
• $\mathrm{Equivalent}\mathrm{weight}=\frac{108}{1}=108\mathrm{g}{\mathrm{mol}}^{-1}$
• Thus, the gram equivalent of silver is, $\mathrm{Gram}\mathrm{equivalent}=\frac{108}{108}=1\mathrm{g}{\mathrm{eq}}^{-1}$

Thus, as per law, “if a one-gram equivalent is deposited with the requirement of one Faraday charge, then a one-gram equivalent of silver will require one Faraday charge only to get deposited.”