00:01
Okay, so you're being asked to find the p -value.
00:04
Anytime you're finding a p -value of any kind, like ph is the most common one, you take the negative log of the concentration of that ion that you happen to be talking about.
00:13
So let's start taking those negative logs for each of these.
00:16
So we've got a sodium ion that we care about, a chloride ion, and a hydroxide ion in a.
00:21
So it says it's 0 .0635 molar in nacl.
00:26
So that means you have 0 .0635 molar na plus and 0 .0635 molar cl minus.
00:34
And it says the hydroxide is 0 .0403 molar.
00:39
So if we find those ps, we can say the p na is going to be equal to, the p cl is going to be equal to, and the p oh is going to be equal to, and we'll just take the negative log of each of these numbers.
00:54
So negative log 0 .0635, that's 1 .2.
01:02
I get three sig figs, so i get three decimal places.
01:05
So 1 .197.
01:07
This one will also be 1 .197 because it's the same numbers...