00:01
This question states that the preparation of aspirin from salicylic acid and acetic anhydride is only 75 % efficient.
00:10
And it wants to know how many grams of salicylic acid do we need in order to get an actual yield of 50 grams of aspirin.
00:27
And before we can start this question, it is useful to write down the molecular weights of both of these compounds of interest, which we can calculate by summing the weights of the atoms which make up each compound.
00:39
So salicylic acid has a molecular weight of 138 .133 grams per mole, and aspirin has a molecular weight of 180 .1 .17 grams per mole.
00:54
So now we want, we know the theoretical yield, or the percent yield of this question to be 75, which is calculated by taking the actual yield, divide by the theoretical yield, and multiplying this by 100, except in this case our actual yield, which we want is 50 grams, and we do not know what is our theoretical yield.
01:24
So if we just rearrange this question and solve for the theoretical yield, we can figure out that the theoretical yield is equal to 66 .67.
01:37
Grams of aspirin and it is with this theoretical yield that we will be doing our remaining calculations with um so first how many mole of aspirin is in 66 .6 .6 .7 grams.
02:01
We can figure this out by dividing the 66 .6 .6g .m...