(a) Will pH value of water be same at temperature `25^(@)C` and `4^(@)C`? Justify in not more than 2 or 3 sentences.
(b) Two student use same stock solution of `ZnSO_(4)` and a solution of CuSO4. The emf of one cell is 0.03 V higher than the other. The concentration of `CuSO_(4)` in the cell with higher emf value is 0.5 M. Find out the concentration of `CuSO_(4)` in the other cell. Given : 2.303RT/F = 0.06V.

Explanation

### Solution:

**(a)** The pH value of water will not be the same at 25°C and 4°C. At 25°C, the pH of pure water is 7, while at 4°C, the self-ionization of water decreases, leading to a lower concentration of H⁺ ions. Consequently, the pH at 4°C will be greater than 7.

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**(b)** To find the concentration of CuSO₄ in the cell with lower EMF, we can use the Nernst equation.

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