which is the limiting reagent?

Question

2.000g C7H6O3(salicylic acid) + 5.00mL C4H6O3(acetic anhydride) -->C9H8O4(asprin) + HC2H3O2(acetic acid)
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Which is the limiting reagent?

How many grams of Asprin should be produced from the reaction mixture?

Answer 1

You're going to need to know the density of acetic anhydride before you can solve this. Basically, you will need to do two different calculations to really know.

Start with your mass of salicylic acid, and using its molar mass calculate the moles of salicylic acid you are beginning with. Since 1 mole of SA forms 1 mole of aspirin, you can determine the theoretical yield by using aspirin's molar mass to convert the moles of aspirin formed into grams of aspirin.

Next, start with your volume of acetic anhydride, and using its density determine the mass of acetic anhydride you began with. Using its molar mass, convert that mass into moles. Again, from your equation, 1 mole of acetic anhydride forms 1 mole of aspirin, so you can determine theoretical yield from acetic anhydride by taking the moles of acetic anhydride and using aspirin's molar mass to calculate grams of aspirin.

Now, of the two initial reactants, the one which gives you the SMALLER yield of aspirin is your limiting reactant. The theoretical yield for your reaction is the mass of aspirin formed using that limiting reactant.