Answer:
The hydroxide [OH-] concentration of the solution is 1.26*10⁻⁵ M.
Step-by-step explanation:
The pOH (or potential OH) is a measure of the basicity or alkalinity of a solution.
POH indicates the concentration of hydroxyl ions [OH-] present in a solution and is defined as the negative logarithm of the activity of hydroxide ions (that is, the concentration of OH- ions):
pOH= -log [OH-]
A solution has a pOH of 4.90. Replacing in the definition of pOH:
4.90= -log [OH-]
Solving:
-4.90= log [OH-]
1.26*10⁻⁵ M= [OH-]
The hydroxide [OH-] concentration of the solution is 1.26*10⁻⁵ M.