posted by Ashley .
I have a question that reads, "What is the pH of a 0.01M (10mM) solution of arginine that has a net charge of -.65?"
I tried using the henderson hasselbach equation, since I know the pka of arginine is 12.48.
So I got pH=12.48+log(b/a)
Since the net charge was -.65, I thought the concentration of base was therefore .65 (and since a+b=1), the acid concentration was .35.
My final answer was 12.75, but I'm not sure if my steps/reasoning are correct.
Your answer is correct.