The pOH of a solution is 6.0. Which statement is correct?

Use [tex] pOH = -\log \left[ OH^{-} \right] [/tex] and [tex] pH + pOH = 14 [/tex].

A. The pH of the solution is 20.0.
B. The concentration of [tex] OH^{-} [/tex] ions is [tex] 1.0 \times 10^{-8} \, M [/tex].
C. The concentration of [tex] OH^{-} [/tex] ions is [tex] 1.0 \times 10^{6} \, M [/tex].
D. The pH of the solution is 8.0.



Answer :

To determine which statements are correct given the pOH of the solution is 6.0, let's follow these steps:

### Step 1: Calculate pH from pOH
Using the relationship between pH and pOH, which is given by:
[tex]\[ pH + pOH = 14 \][/tex]

Substituting the given value of pOH:
[tex]\[ pH + 6.0 = 14 \][/tex]

Solving for pH:
[tex]\[ pH = 14 - 6.0 \][/tex]
[tex]\[ pH = 8.0 \][/tex]

### Step 2: Calculate the concentration of [tex]\([OH^-]\)[/tex] ions from pOH
The relationship between pOH and the concentration of hydroxide ions ([tex]\([OH^-]\)[/tex]) is given by:
[tex]\[ pOH = -\log [OH^-] \][/tex]

Rewriting this equation in terms of [tex]\([OH^-]\)[/tex]:
[tex]\[ [OH^-] = 10^{-pOH} \][/tex]

Substituting the given value of pOH:
[tex]\[ [OH^-] = 10^{-6.0} \][/tex]

Calculating the concentration:
[tex]\[ [OH^-] = 10^{-6} \][/tex]
[tex]\[ [OH^-] = 1.0 \times 10^{-6} \, \text{M} \][/tex]

### Step 3: Validate the given statements

Now, let's check each statement:

1. Statement: The pH of the solution is 20.0.
- From our calculation, [tex]\[ pH = 8.0 \][/tex].
- This statement is incorrect.

2. Statement: The concentration of [tex]\([OH^-]\)[/tex] ions is [tex]\(1.0 \times 10^{-8} \, \text{M}\)[/tex].
- From our calculation, [tex]\[ [OH^-] = 1.0 \times 10^{-6} \, \text{M} \][/tex].
- This statement is incorrect.

3. Statement: The concentration of [tex]\([OH^-]\)[/tex] ions is [tex]\(1.0 \times 10^6 \, \text{M}\)[/tex].
- From our calculation, [tex]\[ [OH^-] = 1.0 \times 10^{-6} \, \text{M} \][/tex], which is vastly different.
- This statement is incorrect.

4. Statement: The pH of the solution is 8.0.
- From our calculation, [tex]\[ pH = 8.0 \][/tex].
- This statement is correct.

### Conclusion
The correct statement given the pOH of the solution is 6.0 is:
- The pH of the solution is 8.0.