Anti Aging Skin Tips

Please please help ASAP! Monochloroacetic acid, HC2H2ClO2, is a skin irritant that is used in "chemical peels"

Please please help ASAP! Monochloroacetic acid, HC2H2ClO2, is a skin irritant that is used in "chemical peels" Monochloroacetic acid, HC2H2ClO2, is a skin irritant that is used in "chemical peels" intended to remove the top layer of dead skin from the face and ultimately improve the complexion. The value of Ka for monochloroacetic acid is 1.35 10-3. Calculate the pH of a 0.10 M solution of monochloroacetic acid.

Public Comments

1. there is a formula for it in the book-get the formula and plug in all the values they give you
2. Here, I'lll give you a hint to start with: [H+] = ? The rest is up to you! You will not learn if I show you how. (I just see katbarf's answer, but he is wrong. Ka is NOT that high; I think he misread that part, thus leading him down wrong path)
3. The Rxn is MCA-> H+ + CA- If we start with 0.1 M MCA and x M is dissociated, at equilibrium, [H+][CA-]/[HCA]= Ka so, x^2/(0.1-x) = 13.5x10^4 (hint, it helps to have an even power here because you will be doing a sqrt operation sooner of later. The "problem" here is that the Ka is relatively high, so the usual assump;tion that x<<0.1 doesn't work. So you either have to solve it as a quadratic or just by trial and error. x is about 0.011 mole/L. So the pH= 2-log (1.1)= 1.95 appx.