Question

What is the hydronium ion concentration of a solution with a pOH of 7.20?

Answer 1

Answer: The concentration of hydronium ions in a solution is $1.58\times 10^{-7}$

Explanation:

We are given:

pOH of the solution = 7.2

To calculate the hydronium ion concentration of the solution, we need to determine the pH of the solution first. And to calculate that we use the equation:

$pH+pOH=14\\pH=14-7.2=6.8$

pH is defined as negative logarithm of hydrogen ion concentration. It is basically defined as the power of hydrogen ions in a solution.

Mathematically,

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

pH of the solution = 6.8

Putting values in above equation, we get:

$6.8=-\log[H^+]$

$[H^+]=antilog(-6.8)$

$[H^+]=1.58\times 10^{-7}$

Hence, the concentration of hydronium ions in a solution is $1.58\times 10^{-7}$

Answer 2

Answer:

[H⁺] = 1.58 x 10⁻⁷ M.

Explanation:

∵ pOH = - log[OH⁻]

7.20 = - log[OH⁻]

log[OH⁻] = - 7.20

∴ [OH⁻] = 6.31 x 10⁻⁸.

∵ [H⁺][OH⁻] = 10⁻¹⁴.

∴ [H⁺] = 10⁻¹⁴/[OH⁻] = 10⁻¹⁴/(6.31 x 10⁻⁸) = 1.585 x 10⁻⁷ M.