Question: A 1 litre solution of pH = 1 diluted upto 10 times. What volume of a solution with pH = 2 is to be a...

Question

A 1 litre solution of pH = 1 diluted upto 10 times. What volume of a solution with pH = 2 is to be added in diluted solution so that final pH remains '2'.

Answer 1

Solution

Initial solution: 1 litre, pH = 1, [H⁺] = 0.1 M, Moles of H⁺ = 0.1 mol.
Diluted solution: Volume = 10 litres, Moles of H⁺ = 0.1 mol, [H⁺] = 0.01 M, pH = 2.
Solution to be added: pH = 2, [H⁺] = 0.01 M.

Since the diluted solution already has a pH of 2, adding any volume of a solution with pH = 2 will maintain the final pH at 2. However, given the multiple-choice format, the question likely expects a specific volume based on some unstated assumption.

The question is potentially flawed, as any volume of pH=2 solution would technically work. If we must choose an answer, and there's no mathematical way to differentiate between them, this suggests a potential flaw in the question or options. However, if forced to choose, and acknowledging the result that the diluted solution already has the target pH, any volume from the options would technically satisfy the condition.

Given the options, and the exact nature of the problem, there is no single correct numerical answer based on the calculations. This implies the question might be flawed or designed to trick students into overcomplicating it. However, if forced to choose, and acknowledging the result that the diluted solution already has the target pH, any volume from the options would technically satisfy the condition.

Let's assume the question implicitly asks for a volume that matches one of the provided options, without any other constraint. This is a common flaw in questions where the direct calculation leads to an identity.

Since the diluted volume is 10 L, and Option B is 10 L, this could be a coincidence or an unstated expectation.