Question #70ea1

1 Answer
May 29, 2016

K_a(HOAc)=1.82xx10^(-5)Ka(HOAc)=1.82×105

Explanation:

H_3C-C(=O)OH +H_2O rightleftharpoonsH_3C-C(=O)O^(-) + H_3O^+H3CC(=O)OH+H2OH3CC(=O)O+H3O+

K_aKa == ([H_3O^+][H_3C-C(=O)O^(-)])/([H_3C-C(=O)OH])[H3O+][H3CC(=O)O][H3CC(=O)OH]

Now it is a given that [H_3O^+][H3O+] == 0.0019*mol*L^-10.0019molL1. Given the stoichiometry of the equation, [HO^-][HO] == 0.0019*mol*L^-10.0019molL1 as well, and [H_3C-C(=O)OH]=(0.200-0.0019)*mol*L^-1[H3CC(=O)OH]=(0.2000.0019)molL1.

Thus K_aKa == (0.0019)^2/(0.200-0.0019)(0.0019)20.2000.0019 == 1.82xx10^(-5)1.82×105.