The pH of a 0.10 M solution of ammonia is 11.1. Find the hydroxide concentration.
pH + pOH = pKw = 14
Solve for pOH, then pOH = -log(OH^-).
pH=11.1, so pOH is 14-11.1=2.9
To find the hydroxide concentration, we can make use of the relationship between the pH and pOH of a solution. The pOH is the negative logarithm of the hydroxide ion concentration (OH-).
First, let's calculate the pOH using the given pH value of 11.1:
pOH = 14 - pH
pOH = 14 - 11.1
pOH = 2.9
Now, we know that pH + pOH = 14 in aqueous solutions at room temperature. Therefore, we can find the hydroxide ion concentration by taking the antilogarithm (inverse logarithm) of the pOH value:
[OH-] = 10^(-pOH)
[OH-] = 10^(-2.9)
[OH-] ≈ 1.26 x 10^(-3) M
Therefore, the hydroxide concentration of the 0.10 M ammonia solution is approximately 1.26 x 10^(-3) M.