Does Adding HCl Change the pH of a CH3COOH/CH3COO Buffer?

[Boxxxed]

Calculate final pH of 25 ml buffer 0.1 M CH3COOH/CH3COO, pH=3.50, after the addition of 1.00 ml of 0.1 M HCl.


3.50=4.75+log(base/3.16x10-4)

Base = 1.78x10-5 M
Acid = 3.16x10-4 M


Mole base = 0.000712 - 0.0001 = 0.000612
Mole Acid = 0.01264 +0.0001 = 0.01274

Mole Acid added = 0.0001 Mole

ph=4.75+log(0.000612/0.01274)

ph = 2.43

Is this correct?

 

[Borek]

Base = 1.78x10-5 M
Acid = 3.16x10-4 M

Total of 3.33x10^-4M, that's not a 0.1M buffer.