The pH of a solution is 2.0. Which statement is correct?

Useful formulas include:
[tex]\[ \left[ H_3O^+ \right] = 10^{-pH} \][/tex]
[tex]\[ \left[ OH^- \right] = 10^{-pOH} \][/tex]
[tex]\[ pH + pOH = 14 \][/tex]
[tex]\[ \left[ H_3O^+ \right] \left[ OH^- \right] = 10^{-14} \][/tex]

A. The pOH of the solution is 12.0.
B. The concentration of [tex]\([OH^-]\)[/tex] ions is [tex]\(1.0 \times 10^{-2} \, M\)[/tex].
C. The concentration of [tex]\([H_3O^+]\)[/tex] ions is 100.0 M.
D. The pOH of the solution is 16.0.



Answer :

Let's analyze each statement given that the pH of the solution is 2.0 and use the useful formulas outlined.

1. The pOH of the solution is 12.0:

To determine the pOH, we use the relationship between pH and pOH:

[tex]\[ \text{pH} + \text{pOH} = 14 \][/tex]

Given that the pH is 2.0, we can solve for pOH:

[tex]\[ \text{pOH} = 14 - \text{pH} = 14 - 2.0 = 12.0 \][/tex]

Hence, the statement "The pOH of the solution is 12.0" is correct.

2. The concentration of [tex]\(\left[ OH^{-} \right]\)[/tex] ions is [tex]\(1.0 \times 10^{-2} \, M\)[/tex]:

To find the concentration of [tex]\(\left[ OH^{-} \right]\)[/tex] ions, we use the calculated pOH.

Using the formula:

[tex]\[ \left[ \text{OH}^{-} \right] = 10^{-\text{pOH}} \][/tex]

With [tex]\(\text{pOH} = 12.0\)[/tex]:

[tex]\[ \left[ \text{OH}^{-} \right] = 10^{-12} \][/tex]

Hence, the statement "The concentration of [tex]\(\left[ OH^{-} \right]\)[/tex] ions is [tex]\(1.0 \times 10^{-2} \, M\)[/tex]" is incorrect. The correct concentration is [tex]\(1.0 \times 10^{-12} \, M\)[/tex].

3. The concentration of [tex]\(\left[ H _3 O ^{+} \right]\)[/tex] ions is 100.0 M:

To find the concentration of [tex]\(\left[ H_3O^+ \right]\)[/tex] ions, we use the pH.

Using the formula:

[tex]\[ \left[ \text{H}_3\text{O}^+ \right] = 10^{-\text{pH}} \][/tex]

With [tex]\(\text{pH} = 2.0\)[/tex]:

[tex]\[ \left[ \text{H}_3\text{O}^+ \right] = 10^{-2} = 0.01 \, M \][/tex]

Hence, the statement "The concentration of [tex]\(\left[ H _3 O ^{+} \right]\)[/tex] ions is 100.0 M" is incorrect. The correct concentration is [tex]\(0.01 \, M\)[/tex].

4. The pOH of the solution is 16.0:

As determined earlier,

[tex]\[ \text{pOH} = 14 - 2.0 = 12.0 \][/tex]

Hence, the statement "The pOH of the solution is 16.0" is incorrect. The correct pOH is 12.0.

Therefore, out of all the statements provided, the only correct statement is: "The pOH of the solution is 12.0."