Calculate the H3O^+ and OH^- ion concentrations in a solution that has a pH of 3.72.
To calculate the H3O+ and OH- concentrations in a solution, we can use the equation for pH:
pH = -log[H3O+],
where [H3O+] is the concentration of H3O+ ions in moles per liter.
First, let's find the H3O+ concentration:
1. Rearrange the equation: [H3O+] = 10^(-pH).
2. Plug in the pH value from the question: [H3O+] = 10^(-3.72).
3. Calculate the value: [H3O+] ≈ 1.37 x 10^(-4) M.
Now, to find the OH- concentration, we can use the relation between the H3O+ and OH- ions in water:
[H3O+][OH-] = 1.0 x 10^(-14) M^2.
Since we already have the [H3O+] value, we can rearrange the equation to solve for [OH-]:
[OH-] = 1.0 x 10^(-14) M^2 / [H3O+].
4. Plug in the [H3O+] value we calculated: [OH-] = 1.0 x 10^(-14) M^2 / 1.37 x 10^(-4) M.
5. Simplify the expression: [OH-] ≈ 7.3 x 10^(-11) M.
Therefore, in a solution with a pH of 3.72, the H3O+ ion concentration is approximately 1.37 x 10^(-4) M and the OH- ion concentration is approximately 7.3 x 10^(-11) M.
pH = -log(H3O^+)
Solve for (H3O^+)
pH + pOH = pKw = 14
Solve for pOH.
pOH = -log)OH^-)
Solve for (OH^-)