Calculate the pH of a Solution?

Question

Calculate the ph of the solution made by adding 0.50 mol of propanoic acid (C2H5COOH or HC3O5H2) and 0.30 mol of sodium propanoate (C2H5COONa or NaC3H5CO2) to 1.00 L of water. The value of Ka for C2H5COOH is 1.3*10^-5.

Answer 1

Best Answer - Chosen by Voters

Equilibrium concentrations will be essentially the same as initial concentrations, so ka=base/acid comes to 1.3*10^-5=x.30/.50 or simplified, 1.3*10^-5=.60x. Divide both sides by .60 to isolate x, you get 2.17*10^-5. If you look at your ICE chart, H3O=x, so -log(2.17*10^-5)=4.66

Source(s):

Reading my Chem textbook.