I wanted to calculate the theoretical and actual yield of aspirin.

mass of salicylic acid = 2.005 g

But isn't salicylic acid differ. from acetic acid? If so, how do we find the mass of acetic acid in this experiment

volume of acetic anhydride = 4 ml

mass of acetic anhydride (use 1.08 g/ml for the liquid density) = (1.08 g/ml)(4 ml)= 4.32 g

moles of acetic anhydride ((CH3CO)2O; molar mass = 86 g) = 4.32 g / 86 g = .0502 mol

mass of filter paper = .196 g

mass of weighing tray = 1.900 g

mass of aspirin, filter paper, and weighing tray = 4.286 g

mass of aspirin = 2.19 g

moles of aspirin (C9H8O4; molar mass = 180 g) = 2.19 g / 180 g = .0121 mol

I know the percent yield is equal to the mass of actual yield divided by the theoretical yield and is multiplied by 100%. Also, there has to be a balanced equation in order to calculate the theoretical yield. But I'm a little confused on how to set up the balanced equation.

1 mol acetic anhydride + 1 mol salicylic acid = 1 mol aspirin

I don't know the formulas (I could look them up but you probably have them) but the above tells you what you want to know. It's a 1:1 ratio throughout.
You will need to calculate the mols salicylic acid and mols acetic anhydride and determine the limiting reagent. Then you can calculate the theoretical yield.

ok thank you

wait, I just have one quick question. I realized the equation for this experiment would be

C7H6O3 + C4H6O3 ----> C9H8O4 + C2H4O2

BUT... acetic acid's formula is C2H402 in molecular formula. Is the above equation right? Also, I realized after mixing salicylic acid and acetic anhydride this yields aspirin and acetic acid. But how do I obtain the mass of acetic acid?

To calculate the theoretical yield of aspirin, you first need to set up a correctly balanced chemical equation. The reaction involved in the synthesis of aspirin is shown below:

C7H6O3 + C4H6O3 → C9H8O4 + HC2H3O2

Based on this equation, salicylic acid (C7H6O3) and acetic anhydride (C4H6O3) react to form aspirin (C9H8O4) and acetic acid (HC2H3O2).

To find the theoretical yield, you need to determine the limiting reactant. This is the reactant that is completely consumed in the reaction and limits the amount of product that can be formed. The stoichiometry of the balanced equation will help you identify the limiting reactant.

To find the mass of acetic acid, you need to first calculate the moles of acetic anhydride used. You have already calculated that the moles of acetic anhydride is 0.0502 mol. Since the balanced equation shows that 1 mol of acetic anhydride produces 1 mol of acetic acid, the moles of acetic acid will also be 0.0502 mol.

To find the mass of acetic acid, you multiply the moles by its molar mass (measured in grams per mole), which is 60 g/mol. Thus, the mass of acetic acid is:

mass = moles × molar mass
mass = 0.0502 mol × 60 g/mol
mass = 3.012 g

Now that you have the mass of acetic acid, you can calculate the theoretical yield of aspirin. The theoretical yield is the maximum amount of product that can be obtained from the given reactants assuming a 100% yield. As per the balanced equation, every mole of salicylic acid (C7H6O3) reacts with one mole of acetic acid (HC2H3O2) to produce one mole of aspirin (C9H8O4). Therefore, the theoretical yield of aspirin can be calculated using the stoichiometry of the reaction.

Since you have 2.005 g of salicylic acid, you can convert this mass to moles using its molar mass (measured in grams per mole), which is 138 g/mol:

moles = mass / molar mass
moles = 2.005 g / 138 g/mol
moles = 0.0145 mol

Therefore, the theoretical yield of aspirin is 0.0145 mol.

To calculate the percent yield, you need to divide the actual yield (which is given as 2.19 g) by the theoretical yield (0.0145 mol), and then multiply by 100%:

percent yield = (actual yield / theoretical yield) × 100%
percent yield = (2.19 g / 0.0145 mol) × 100%
percent yield = 15100%

Therefore, the percent yield of aspirin in this experiment is 15100%.