Question

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

• A. 1 litre
• B. 10 litre
• C. 100 litre
• D. 25 litre

Answer 1

Answer: (A), (B), (C), (D)

The correct options are
A 1 litre
B 10 litre
C 100 litre
D 25 litre

Before dilution, the pH is 1. This corresponds to 0.1 M hydrogen ion concentration.
When the solution is diluted 10 times, its hydrogen ion concentration will be 0.01 M $\Rightarrow$ pH =2.

To this solution, when a solution with pH = 2 is added, the hydrogen ion concentration and pH of the resulting mixture will remain the same. This is irrespective of the volume of the solution added.