A 0.01m aqueous NaOH solution has a hydroxide concentration of

Sodium hydroxide, or NaOH, is made up of two
ions: the sodium ion (Na+, also known as the cation or positive ion) and the hydroxide ion (OH-,
also known as the anion or the negative ion). Each molecule of sodium hydroxide is made up of
one ion each of sodium and hydroxide. Thus, one mole of sodium hydroxide will consist of one
mole each of sodium ions and hydroxide ions.

Here, we have 0.01 M aqueous
solution of sodium hydroxide. In other words, this is 0.01 moles of sodium hydroxide in a
solution volume of 1 L. As per the above explanation, 0.01 moles of sodium hydroxide will be
made up of 0.01 moles of sodium ions and 0.01 moles of hydroxide ions.

Now,
sodium hydroxide is a strong base and hence instantly dissociates into its constituent ions upon
dissolution in water.

NaOH -> Na+ + OH-

The 0.01 M solution of sodium hydroxide will contain 0.01 moles of
sodium and 0.01 moles of hydroxide ions in 1 L of solution. The concentration of hydroxide ions
in such a solution is 0.01 M.

We can also use
this concentration to determine the pH of the solution. With a hydroxide concentration of 0.01
M, the pOH of the solution is 2.

Using the relationship between pH and pOH of
a solution (pH + pOH = 14), we can figure out the pH of the solution as 12 (= 14 - 2). This pH
makes sense, given that sodium hydroxide is a strong base.

Hope this
helps.