Calculate pH of an acetate buffer containing 27.5 mM acetic acid (pKa is 4.74) and 50 mM

Question

sodium acetate. When a 30 mM aq solution of sodium acetate was prepared in the lab it had a pH
of 8.8. Calculate the amount of acetic acid (in g) to be added to 0.5 L of this sodium acetate
solution in order to bring its pH to the target value of 5.00.

Answer 1

I worked this below. I can find it if you wish.

Answer 2

im just stuck on how to do the last part.

5.00 = 4.74 + lot (15/x)
Solve for x = millimoles acetic acid and convert that to grams in 500 mL solution ? thank you very much

Answer 3

Your problem isn't chemistry. You just need a little help with algebra.
5.00-4.74 = 0.26 = log 15/x
15/x = antilog 0.26 = 1.82
So 1.82 = 15/x. Solve for x and convert to g/500 mL.

Answer 4

That's brilliant help :) thank you so much