Chemistry Help?

Question

Calculate the pH of a 100 mL solution of 0.100 M acetic acid (HC2H3O2) which has a Ka value of 1.8*10^(-5).

Answer 1

Step 1:

The concentration of acetic acid is [HCH₂H₃O₂] is 0.100 M.

k_a for acetic acid is .

The equation is .

Equlibrium Constant : .

generates one mole of and one mole of .

Let then .

                 

Step 2:

Find the pH of the solution.

Definition of pH: .

The pH of the solution is 2.8729.

Solution:

The pH of the solution is 2.8729.