Question

Determination of pH of acid solution like 0.1m HCl and 0.05m HCl . 0.025m HCl and 0.0125m HCl by using calomel electrode. Compare the theoretically calculated value.

Answer 1

The potential of quinhydrone electrode at 25 C is 0.6992 V whereas that of calomel electrode is 0.2438 V. The total potential can be written as E = E(quin. or cal.) - E(2H+/H2). Potential of the hydrogen electrode in a respective solution will be E = -0.059*lg(H+). Thus, E(quin.) = 0.6992 V - (-0.059*lg(H+)) or E(cal.) = 0.2438 V - (-0.059*lg(H+)). However, to compare these calculations with some practical results we need to have some practical results. Thus, please give your data and I will compare them.
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