Question

Determine the volumes of 0.10 M CH3COOH and 0.10 M CH3COONa required to prepare 10.0 mL of buffer of each of the following pH values?

a. Ph 3.7
b. pH 5.7
C. pH 5.7

I just need to see how to do one of them and I'll understand how to do the rest.

Answer 1

Plug and chug into the HH equation.
These problelms, where no concentration is given for the buffer, is a wide open problem with no restrictions. Here is what you do.
Let x volume(in mL) CH3COONa and 10-x = volume in mL of CH3COOH.
pKa CH3COOH is about 4.74 but you need to use the value in your text.
3.7 = 4.74 + log (0.1x)/0.1(10-x)
Solve for x ad 10-x

Answer 2

1.5

Answer 3

pH = pka + log [base CH3COONa]/[acid CH3COOH]
3.7 = 4.7 + log [base]/[acid]
alegbra to remove 4.7 from both sides
-1.0 = log [base]/[acid]
log= 10^x so alegbra to remove 10^x
10^-1 = [base]/[acid] or 0.10 = [base]/[acid]
1 ml for base added to 9 ml of acid

Answer 4

2.4