Question

Consider the cell Cu/Cu+2|| Ag+/Ag. If the concentration of Cu+ and Ag+ ions becomes 10 times the emf of cell :
a) becomes 10 times
b) Remains same
c) Increase by 0.0295V
d) Decrease by 0.0295V

Answer is (c). Please elaborate how​

Answer 1

Answer:    The answer is (c) Increase by 0.0295V .

      Increase in the amount of the Materials of cell emf increases.

Explanation:

As given that unit concentrations increased by factor of 10 then E₀ Values are:

Cu⁺² +2e ⇄ Cu     E₀ = +0.34 V

Ag⁺² +  e ⇄ Ag     E₀ = +0.8 V

The Cell Reactioon can be written as :

Cu+ 2 Ag⁺ ⇒ Cu⁺²  + 2 Ag

E₀ = +0.8 V-0.34 V = 0.46 V

Hence concentration effect can be shown by Nernest Equation:

                        Ecell = E₀cell = ((RT/ zF) ln Q

hnce quation can be simplified by putiiong the values

$E_{cell }=E_{o}-( \frac{0.0591}{2}) log \frac{[Cu^{+2}]}{[Agx^{+2}]} \\Increasing \ the \ concerntration \ by \ 10th \ factor \ and \ simplyfing, \\E_{cell }=0.46-( \frac{0.0591}{2}) log \frac{10}{10^{10}}\\E_{cell }=0.46+0.02955\\E_{cell }=0.49V$

There is slight increase in emf of the cell,as the Amount of materials in  the cell is increased, amount of current drawn from it also increases.

Hope you find it helpful :)