explain why pH is useful way of describing acid and base solutions over a very wide range of concentrations?

Answers:
pH is negative log of the concentration of hydrgen ions.So pH of 1 would mean 10^(-1) or 0.1 concentration of hydrogen ion.pH of 14 would mean 10^(-14) or 0.00000000000001 concentration of hydrogen ions.That would mean that with a no. between 1 and 14 we can express a very wide range of concentrations.

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To cut to the chase.In any solution, there is a concentration of 'free' hydrogen ions. (In actual point of fact, they are massively solvated, but that's a side point.) The negative of the logarithm of that concentration is the pH.Why is it so useful? Because it easily and compactly expresses a quantity--the relative concentrations of 'free' hydrogen ions--that describes the relative acidity or alkalinity of a given solution with considerable precision.Or, in short: it's useful because it works easily and well.

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