Answer: The hydroxide ion concentration in the solution is

Step-by-step explanation:
pOH is defined as the negative logarithm of hydroxide ion concentration present in the solution.
The equation used to calculate pOH of the solution is:
![pOH=-\log[OH^-]](https://img.qammunity.org/2020/formulas/chemistry/high-school/n477c3o3xy8p6ug3ipfjqh9fd53hdrrjyq.png)
We are given:
pOH = 10.75
Putting values in above equation, we get:
![10.75=-\log[OH^-]](https://img.qammunity.org/2020/formulas/chemistry/middle-school/hi5ag6zc9zc0u7whs6r4wrbqko6eqbt6zb.png)
![[OH^-]=10^(-10.75)=1.778* 10^(-11)M](https://img.qammunity.org/2020/formulas/chemistry/middle-school/h331bc6tesmkipzf7hcx6moqovf36uc057.png)
Hence, the hydroxide ion concentration in the solution is
