# Chemistry

posted by .

You want to make 1000 ml of an 0.1 M HA buffer so that the pH=pKa of HA. To make this buffer you need to add ____ HA and ____ mL of 1M NaOH and then add enough water to give 1000 mL. HA is a weak acid.

• Chemistry -

pH = pKa + log{[A-]/[HA]}
or
pH = pKa + log{[NaA]/[HA]}
if pH = pKa, then {[log{[NaA]/[HA]} = 0
or [NaA] = [HA]
The reaction between NaOH and HA is:
NaOH + HA --> NaA + H2O
That happens when we neutralize HALF of the HA by using NaOH. The mole ratio of NaOH added to HA is 1 to 2 or 1/2.
I gave you most of the solution of the problem. You should be able to finish it on your own.

## Similar Questions

1. ### chemistry-buffer

Buffer question: If I add 3 mL of 1 M NaOH to a buffered solution, will I still have a valid buffer?
2. ### CHEMISTRY HELP!

(1) A beaker with 165 mL of an acetic acid buffer with a pH of 5.00 is sitting on a bench top. The total molarity of the acid and conjugate base in the buffer is 0.100M. A student adds 7.20mL of a 0.320M HCl solution to the beaker. …
3. ### chemistry

If you add 5.0 mL of 0.50 M NaOH solution to 20.0 mL to Buffer C, what is the change in pH of the buffer?
4. ### college chem

a. According to the Henderson-Hasselbalch equation, how many grams of sodium acetate will you need to add to 125 mL of 0.100 M acetic acid to make a pH=4.74 buffer?
5. ### CHEMISTRY HELP!

a. According to the Henderson-Hasselbalch equation, how many grams of sodium acetate will you need to add to 125 mL of 0.100 M acetic acid to make a pH=4.74 buffer?
6. ### biochem

I need to create a 100ml buffer with a pH of 4.00 using 0.100M Benzoic acid (pKa = 4.20)and 0.180M sodium benzoate. What volume of each material do I need to make this buffer?
7. ### Chemistry

Q1: You wish to prepare a buffer solution with pH = 11.10. What volume of 6.0 M HCl would you add to 500 mL of 0.10 M (C2H5)2NH to prepare the buffer?
8. ### Chemistry

Q1: You wish to prepare a buffer solution with pH = 11.10. What volume of 6.0 M HCl would you add to 500 mL of 0.10 M (C2H5)2NH to prepare the buffer?
9. ### CHEMISTRY

I have trouble how to resist pH in buffer solutions ( in acidic buffer , and in basic buffer ) when we add an acid , and a base ! how the reactions in buffer follow Le chatlier's principle ?
10. ### chemistry

A buffer is prepared consisting of 0.75 mol of sodium dihydrogenphosphate, NaH2PO4, and 0.60 mol of sodium hydrogenphosphate, Na2HPO4, dissolved in 600.0 mL of water. The Ka for the dihydrogenphosphate ion is 6.2 x 10–8 at 25°C. …

More Similar Questions