To calculate the pOH of a solution with a pH of 10.7, we can use the following formula:

```

pOH = 14 - pH

```

Where:

- pOH is the negative logarithm of the hydroxide ion concentration ([OH-]) in moles per liter (mol/L).

- pH is the negative logarithm of the hydrogen ion concentration ([H+]) in moles per liter (mol/L).

Substituting the given pH value of 10.7 into the formula, we get:

```

pOH = 14 - 10.7 = 3.3

```

Therefore, the pOH of the solution is 3.3.