From the problem I can tell that you already have a chemical equation. The formula for a synthesis reaction of salicylic acid and acetic anhydrid is C7H6O2 + C4H6O3 --> C9H8O4 + C2H4O2.
First you have to change salicylic acid and acetic anhydride from g to mol so that you can figure out the limiting reactant. So find out how many g / mol in each of these reactants by adding up all of the atomic masses.
In C7H6O3 the g/ mol is:
7(12.011) + 6 (1.008) + 3 (15.999) = 138.12 g / mol
In C4H6O3 the g / mol is:
4 (12.011) + 6 (1.008) + 3 (15.999) = 102.089
Then find mol of each
11.2g C7H6O3 * (1 mol / 138.12 g) = .0818 mol C7H6O3
18.2 g C4H6O3 * (1 mol / 102.089g) = .1783 mol C4H6O3
So know we know the limiting reactant is is the salicylic acid. Now find how many mol of aspirin could be made from .0818 mol C7H6O3. We know from the equation the 1 mol aspirin is equal to 1 mol salicylic acid in this problem.
.0818 mol C7H6O3 * (1 mol C9H8O4 / 1 mol C7H6O3) = .0818 mol C9H8O4
Now you have to find out how many g are in a mol of C9H8O4
9 (12.011) + 8(1.008) + 4 ( 15.999) = 180.159 g / mol
Finally multiply mol by g / mol of C9H8O4
.0818 mol * (180.159 g / 1 mol) = 14.737 g C9H8O4
So you can make 14.737 g of aspirin with the ingredients listed.
Content will be erased after question is completed.