00:01
Hi, so in this case we are going to have a 25 milliliter sample of sodium hydroxide that is going to be titrated to the equivalence point with 18 .45 milliliters of a 0 .1 molar solution of sulfuric acid.
00:21
So in order to know the concentration of the sodium hydroxide that we had at the very beginning, we need to calculate the amount of mole that we added of sulfuric acid.
00:30
And remember that in this case we are going to have a 2 to 1 correspondence for the reaction.
00:37
So the reaction between sulfuric acid and sodium hydroxide, we are going to have two equivalents of sodium hydroxide reacting with the sulfuric acid to generate water.
00:53
In this case we are going to have two equivalents of water plus sodium sulfate.
01:03
So here we have the 2 to 1 correspondence in our equation.
01:09
So the amount of mole of sulfuric acid that we added is going to be equal to volume times the concentration in molarity.
01:21
The volume in this case is 18 .45 milliliters but we need to convert that into liters.
01:26
We can do it simply by multiplying by times 10 to the minus 3 times the concentration in molarity that we have...