Next we need to add a few drops of an acid base indicator.
So to this flask we're also going to add a few drops of an acid base indicator. And phenolphthalein is colorless in acid but turns pink in the presence of base.
The stoichiometric equivalence must be borne in mind, when you do the calculation.
So, as a general rule, you must have the appropriate, stoichiometrically balanced chemical equation.
And then if we divide by 20 we will get our answer of zero point two four three. And this shortcut way works pretty well when you're dealing with a strong acid and a strong base and a one to one molar relationship.
Alright in the next video we'll do a problem where the mol ratio is no longer one to one.
And here we stop and we check and see the volume of base that we used in our titration.
So if we started right here, if we started with that much base, let's say we ended down here, alright? And this would be the volume of base that we used in the titration.
Alright so we have a change in volume here, and let's say that it's 48.6 milliliters.
So it took 48.6 milliliters of our base to completely neutralize the acid that we had present.