00:01
To calculate the ph of the buffer, we use the henderson -hasselbalch equation.
00:06
Ph is equal to pca plus the log of the concentration base over concentration acid, or moles base over moles acid.
00:21
Either ratio works.
00:23
So, ph will be equal to pca, which is the negative log of the acid, in this case, hydrozoic acid pca will be the negative log of the ka value at 1 .9 times 10 to the negative 5 plus the log of the moles of base that is the sodium hydrozoate at 0 .37 divided by the moles of acid at 0 .14 and we get 5 .14 now when we add sodium hydroxide, represented as hydroxide, it's going to react with the acid hn3, and in the process, produce n3 minus, plus water.
01:41
So every mole of hydroxide we add, consumes the mole of the acid, and makes a mole of the base.
01:48
This then allows us to use the henderson -hasselbalch equation again with a slight modification.
02:05
The moles of base are going to be equal to the 0 .37 plus the moles of strong base added, 0 .03...
