Is the Final pH Calculation Correct?

[em-kay]

Homework Statement

What will be the final pH of the solution if a drop (approximately equal to 1/20 mL) of 1.0M HCl is added to a 10mL 0.1 M CH3COOH sol'n?

Homework Equations

pH = -log [H+]

The Attempt at a Solution

I first determined the number of moles of H+ from the partial ionization of CH3COOH (CH3COOH <--> CH3COO- + H+) using the ICE table. The number of moles H+ from my computation is 4.024922359 x 10^-5.

Then I also determined the number of moles of H+ from HCl--> H+ + Cl-. What I got is 5 x 10^-5 moles.

I added the two values to get the total number of moles H+.

The pH I got is 2.52.


Is my answer correct?
I'm not quite sure about how I solved it.
Need help. Thanks.

 

[em-kay]

How do I apply the common-ion effect for this problem?

 

[Borek]

Do an ICE table for acetic acid treating H⁺ from HCl as initial concentration.

 

[em-kay]

Thanks much. I'll do that.