What is the theoretical yield of aspirin if you have 2g of salicylic acid and 5 ml acetic anhydride?
Use this example. I assume salicylic acid is the limiting reagent.
http://www.jiskha.com/science/chemistry/stoichiometry.html
To calculate the theoretical yield of a chemical reaction, you need to know the balanced chemical equation and the molar masses of the reactants and products. In this case, we need the balanced equation for the reaction between salicylic acid and acetic anhydride to form aspirin.
The balanced equation is:
C7H6O3 + (C4H6O3)2 → C9H8O4 + 2C2H4O2
From the equation, we can see that 1 mol of salicylic acid (C7H6O3) reacts with 1 mol of acetic anhydride (C4H6O3) to produce 1 mol of aspirin (C9H8O4) and 2 mol of acetic acid (C2H4O2).
Now, we need to calculate the number of moles of salicylic acid and acetic anhydride using their molar masses.
The molar mass of salicylic acid (C7H6O3) is:
(7 × atomic mass of carbon) + (6 × atomic mass of hydrogen) + (3 × atomic mass of oxygen)
The molar mass of acetic anhydride (C4H6O3) is:
(4 × atomic mass of carbon) + (6 × atomic mass of hydrogen) + (3 × atomic mass of oxygen)
Once you know the molar masses, you can calculate the number of moles of salicylic acid and acetic anhydride by dividing their respective masses (given as 2g and 5ml) by their molar masses.
Finally, we can use stoichiometry to determine the theoretical yield of aspirin. Since the balanced equation shows that the reaction produces a 1:1 ratio between salicylic acid and aspirin, the number of moles of aspirin will be the same as that of salicylic acid.
To calculate the theoretical yield of aspirin, multiply the number of moles of salicylic acid by the molar mass of aspirin. This will give you the mass (in grams) of aspirin that could be obtained under ideal conditions.
Remember, the theoretical yield represents the maximum amount of product that can be obtained assuming a 100% efficient reaction with no side reactions or losses. In practical scenarios, the actual yield may be lower due to various factors.
So, to find the theoretical yield of aspirin, you need the balanced chemical equation, the molar masses of the reactants, and the masses or volumes of the reactants.