Question

How many times concentrated will be the aqueous solution having pH 11.9 as compared to aqueous solution having pH 8 ?

Page 152 Chapter - 7.Acids, Bases and Salts

Answer 1

Answer:

The aqueous solution having pH 8 is 7937 times more concentrated than the aqueous solution having pH 11.9

Explanation:

pH of the first  aqueous solution = 11.9

We know that if $[H^+]$ is the concentration of the $H^+$ ions then the pH is given by

$\boxed{pH=-\log_{10}[H^+]}$

$\implies \boxed{[H^+]=10^{-pH}}$

Therefore the concentration of $H^+$ ions in the aqueous solution of pH 11.9 is

$[H^+]_{1}=10^{-11.9}=10^{-11}\times10^{-0.9}=1.26\times 10^{-12}$

The concentration of $H^+$ ions in the aqueous solution of pH 11.9 is

$[H^+]_{2}=10^{-8}$

Therefore

$\frac{[H^+]_2}{[H^+]_1} =\frac{10^{-8}}{1.26\times 10^{-12}} =\frac{10000}{1.26} = 7936.5$ ≈ 7937

Therefore, the aqueous solution having pH 8 is 7937 times more concentrated than the aqueous solution having pH 11.9