Question

Calculate the acetate ion concentration in a solution prepared bydissolving 3.80×10^-3 mol of HCl(g) in 1.00 L of 2.00 Maqueous acetic acid (Ka = 1.80×10^-5).

Calculate the pH of the above solution

My work :

Ka = product/ reactant
1.8 x 10^-5 = [CH3COOCl][H2O] / [HCl][CH3COOH]
1.8 x 10^-5 = [CH3COOCl][1] / [3.8 x 10^-3 M][2M]
CH3COOCl = 0.006

But this is incorrect. What am I doing wrong? Thank you for yourtime!

Answer 1

The work is correct. But your answer is wrong. Check thealgebra.
1.8 x 10^-5 = [CH3COOCl][1] / [3.8 x 10^-3 M][2M]
CH3COOCl = 1.406e-7 M