Select the correct answer.

A solution has a pOH of 8.20. What is the concentration of [tex]$H_3O^+$[/tex]?

A. [tex]6.3 \times 10^{-9}[/tex]
B. [tex]1.6 \times 10^{-6}[/tex]
C. [tex]2.0 \times 10^{-6}[/tex]
D. [tex]10.2 \times 10^8[/tex]



Answer :

To determine the concentration of [tex]\( \text{H}_3\text{O}^+ \)[/tex], we can follow a systematic approach involving the relationship between pH and pOH, and the formula for calculating the hydronium ion concentration from pH.

1. Given Data:
- pOH of the solution is 8.20.

2. Determine the pH:
- The relationship between pH and pOH is given by the equation:
[tex]\[ \text{pH} + \text{pOH} = 14 \][/tex]
- Therefore, we can find pH as:
[tex]\[ \text{pH} = 14 - \text{pOH} \][/tex]
- Substituting the given pOH:
[tex]\[ \text{pH} = 14 - 8.20 = 5.80 \][/tex]

3. Calculate the concentration of [tex]\( \text{H}_3\text{O}^+ \)[/tex]:
- The concentration of [tex]\( \text{H}_3\text{O}^+ \)[/tex] ions can be found using the formula:
[tex]\[ [\text{H}_3\text{O}^+] = 10^{-\text{pH}} \][/tex]
- Substituting the calculated pH:
[tex]\[ [\text{H}_3\text{O}^+] = 10^{-5.80} \][/tex]
- Evaluating this expression gives:
[tex]\[ [\text{H}_3\text{O}^+] \approx 1.6 \times 10^{-6} \][/tex]

So, the correct concentration of [tex]\( \text{H}_3\text{O}^+ \)[/tex] is:
[tex]\[ 1.6 \times 10^{-6} \][/tex]

Therefore, the correct answer is:

B. [tex]\( 1.6 \times 10^{-6} \)[/tex]