"What is the pH of a solution that is 0.50 M in sodium acetate and 0.75 M in acetic acid? (Ka for acetic acid is 1.85 x 10-5)."
Would i use the Ka expression formula??
Would i divide the M and then multiply by Ka?
3.03
Yes, you would use the Ka expression formula to calculate the pH of the solution. The Ka expression for acetic acid is as follows:
Ka = [H+][C2H3O2-] / [HC2H3O2]
To solve for the pH, you need to find the concentration of the hydrogen ion (H+) in the solution. However, since the solution contains both acetic acid and sodium acetate, you need to consider the ionization of acetic acid and the hydrolysis of sodium acetate.
First, calculate the concentration of the acetic acid and the acetate ion (C2H3O2-):
[C2H3O2-] = 0.50 M (concentration of sodium acetate)
[HC2H3O2] = 0.75 M (concentration of acetic acid)
Next, calculate the concentration of the hydrogen ion using the following equation:
[H+] = √(Ka * [HC2H3O2] / [C2H3O2-])
Substitute the values:
[H+] = √((1.85 x 10^-5) * (0.75) / (0.50))
[H+] ≈ 1.17 x 10^-3 M
Finally, calculate the pH using the following equation:
pH = -log10[H+]
Substitute the value of [H+] you just calculated:
pH ≈ -log10(1.17 x 10^-3)
pH ≈ 2.93
Therefore, the pH of the solution that is 0.50 M in sodium acetate and 0.75 M in acetic acid is approximately 2.93.