Hey, all. I posted here yesterday asking a similar question. This time, though, I'm having problems calculating the pH of a solution. Here's the question:
19.21 mL of 0.1679 M aqueous HCl is added to 20.68 mL of 0.2752 M aqueous NaOH at 25°C. Assuming the volumes are additive, what is pH of the resulting solution?
I started off by calculating the number of moles of HCl and NaOH (0.003225 and 0.005091, respectively).
Shouldn't I be able to calculate [OH-] like so: (0.005091 - 0.003225)/0.03989 = 0.04677
Then, since I have [OH-], I could do this: -log(0.04677) to obtain pOH, and then 14 - pOH to get pH.
The answer I get from this isn't being accepted.