Sometimes the basicity of a solution is reported using pOH (pOH = -log[OH-]). What is the
a. [OH-] if pOH = 1.90
b. [H3O+] if pOH = 12.94
c. pH if pOH = 9.70
If you know H^+ or OH^- the other can be calculated from
(H^+)(OH^-) = Kw = 1E-14
If you want pH
pH = -log(H^+)
If you want pOH
pOH = -log(OH^-)
If yo have pH or pOH and want the other one
pH + pOH = pKw = 14
To find the concentration of hydroxide ions ([OH-]), the concentration of hydronium ions([H3O+]), and the pH value based on the given pOH values, we can use the following formulas:
a. [OH-] = 10^(-pOH)
b. [H3O+] = 10^(14 - pOH)
c. pH = 14 - pOH
Let's calculate each of these values using the provided pOH values:
a. [OH-] if pOH = 1.90:
Using the formula [OH-] = 10^(-pOH), substituting pOH = 1.90:
[OH-] = 10^(-1.90)
Using a calculator, we find:
[OH-] ≈ 0.01259 M
So, the concentration of hydroxide ions in the solution would be approximately 0.01259 M.
b. [H3O+] if pOH = 12.94:
Using the formula [H3O+] = 10^(14 - pOH), substituting pOH = 12.94:
[H3O+] = 10^(14 - 12.94)
Using a calculator, we find:
[H3O+] ≈ 6.501 x 10^(-2) M
So, the concentration of hydronium ions in the solution would be approximately 6.501 x 10^(-2) M.
c. pH if pOH = 9.70:
Using the formula pH = 14 - pOH, substituting pOH = 9.70:
pH = 14 - 9.70
Calculating:
pH ≈ 4.30
So, the pH value of the solution would be approximately 4.30.