Question

n aqueous solution at has a concentration of . Calculate the concentration. Be sure your answer has 1 significant digits.

Answer 1

The question is incomplete, here is the complete question:

An aqueous solution at 25°C has a $H_3O^+$ concentration of $8.8\times 10^{-12}M$ . Calculate the $OH^-$ concentration. Be sure your answer has the correct number of significant digits.

Answer: The hydroxide ion concentration of the solution is $0.1\times 10^{-2}M$

Explanation:

To calculate the pH of the solution, we use the equation:

$pH=-\log[H_3O^+]$

We are given:

$[H_3O^+]=8.8\times 10^{-12}M$

Putting values in above equation, we get:

$pH=-\log (8.8\times 10^{-12})\\\\pH=11.05$

To calculate the hydroxide ion concentration, we first calculate pOH of the solution, which is:

pH + pOH = 14

$pOH=14-11.05=2.95$

To calculate hydroxide ion concentration of the solution, we use the equation:

$pOH=-\log[OH^-]$

We are given:

pOH = 2.95

Putting values in above equation, we get:

$2.95=-\log[OH^-]$

$[OH^-]=10^{-2.95}$

$[OH^-]=1.12\times 10^{-3}M=0.1\times 10^{-2}M$

Hence, the hydroxide ion concentration of the solution is $0.1\times 10^{-2}M$