Whats the ph of this buffer solution

1.what is the ph for each of these
i)A 0.0100 M aqueous solution of acetic acid [pKa 4.77].
ii)A 0.0100 M aqueous solution of ammonia [pKa 9.25, pKw14.0].

2.Determine the pH of a buffer solution made by combining equal volumes of 0.0100 M acetic
acid and 0.0200 M sodium acetate

1. i) Okay, well Acetic Acid dissociates into CH3COO- and H+, but only partially because it is a weak acid.

pKa = -logKa, so Ka = 1.69824365x10^-5. Ka = (H+)(CH3COO-) / (.01). We assume that the amount dissociated is negligible compared to the amount of acetic acid, so we keep acetic acid as .01.

1.69824365x10^-5 = X^2 / .01. Therefore, X = 4.121x10^-4, which is the [H+] and [CH3COO-]

-log[4.121x10^=4] = 3.385 pH, or 3.39 if you round to 3 sig figs.

ii) NH3 + H2O --> NH4 + OH-.

pKb + pKb = 14. Therefore, the pKb of ammonia is 4.75. -4.75 = logKb, so Kb ammonia is 1.77827941x10^-5.

1.77827941x10^-5 = [OH-][NH4] / [.01]. We solve it the same way as in the previous problem, so x = .0421696503 = [OH-] . -log[.0421696503] = pOH = 1.375.

pH = 14-pOH. 14-1.375 = 12.625 pH

2. The pH of a buffer solution = pKa + log([salt]/[acid]).

acetic acid is acid
ammonia is basic, or alkalinic or whatever
should cancel out or whatever
id guess around 8.5ish on ph scale
preferably get ph paper or sumtin