00:01
To rank these in order of increasing ph, where one is the lowest ph, and 7 is the highest ph, we need to identify them as weak acids, weak bases, strong acids, strong bases, or neutral salts.
00:15
The first one, hoi, is a weak acid.
00:18
It has a ka of 2 times 10 to negative 11.
00:23
Nacn, n -a comes from the strong base sodium hydroxide and does not affect ph, but cn comes from the weak acid, hydrocyanic acid, so cn minus is the conjugate base to hcn.
00:37
So it's a weak base with the kb value that will be equal to the ka value of hydrosyanic acid divided into kw or 1 .6 times 10 to the negative 5.
00:49
H2s .o4, you should have memorized as a strong acid.
00:54
K -n -03, k comes from the strong base, potassium hydroxide, nitrate comes from the strong acid, nitric acid.
01:03
If we have ions coming from strong acids and strong bases, they don't affect ph.
01:08
So this is a neutral salt.
01:12
Then h2 and n .h3, cl, cl comes from the strong acid, hydrochloric acid, and does not affect ph.
01:20
But everything else is the conjugate acid to hydrazine, which is a weak base.
01:28
So it itself is a weak acid with a k -a value.
01:32
That'll be equal to kw divided by the kb value of hydrazine...