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

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The discussion focuses on calculating the final pH of a 25 ml buffer solution consisting of 0.1 M acetic acid (CH3COOH) and its conjugate base acetate (CH3COO) after the addition of 1.00 ml of 0.1 M hydrochloric acid (HCl). The initial pH of the buffer is 3.50, and calculations reveal that after the addition of HCl, the final pH is 2.43. The calculations involve determining the moles of acid and base before and after the addition of HCl, confirming that the buffer capacity is affected by the addition of strong acid.

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Boxxxed
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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?
 
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Boxxxed said:
Base = 1.78x10-5 M
Acid = 3.16x10-4 M

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

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