What are the pH values of the following solutions?
a) 0.15 M HNO3
b) 0.15 M NaOH
c) 1.5 x 10 (-3) M HNO3
d) 1.5 x 10 (-3) M NaOH
I know since HNO3 is 100% dissociated, you can calculate it straight out. Therefore, I think a is .82 and c is 2.82. I'm not sure if I'm right, however. I have no clue how to work b and d. If anyone could help, I'd be really grateful.
2007-01-24 14:44:17 · 2 answers · asked by justinz_1fan 2 in Science & Mathematics ➔ Chemistry
pH = -log[H+] ..... So for the acids just take the - log of their concentrations. c= -log[1.5 x 10-3]
pH + pOH = 14
pH = 14 - (-log[OH-]) then b = 14 - (-log[0.15])
You can do that on your calculator. d is worked the same way.
2007-01-24 14:54:42 · answer #1 · answered by docrider28 4 · 0⤊ 0⤋
Your answers for a and c are correct. For b and d, you have bases which will dissociate completely, so what you want to do is calculate pOH = -log[OH-]. Then once you have pOH, pH = 14 - pOH.
So for b, pH = 14 - -log(.15) = 13.18
2007-01-24 14:55:48 · answer #2 · answered by boarderx13132000 2 · 0⤊ 0⤋