Synthesis Of Aspirin

Question 1

What are the characteristics of aspirin?

Answer 1

It is the trade name for acetylsalicylic acid (ASA)

• analgesic (pain-killer)
• antipyretic (fever-reducing)
• vasodialator

Question 2

How is aspirin prepared?

Answer 2

Its an Esterification reaction, the reaction between carboxylic acids (acetic or ethanoic) with alcohols (ethanol) forming an ester (R-C(=O)-OH) & water it is a reversible reaction so you can shift it towards the synthesis of aspirin by adding a mineral acid

Aspirin is prepared by the addition of salicylic acid (acts as an alcohol) with acetic anhydride (carboxylic acid) forming acetylsalicylic acid (Aspirin) and acetic acid

Question 3

How can you calculate the theoretical yield?

Answer 3

Theoretical yield is the amount of product that you would get if all the limiting reagent reacted and it is measured from the moles of the limiting reactant

Question 4

How to calculate the actual yield?

Answer 4

The amount of product actually obtained from a reaction based on the mass of the product

Question 5

How to calculate the percentage yield obtained?

Answer 5

%yield = actual yield/theoretical yield * 100

Question 6

How to find the limiting reactant?

Answer 6

Because it is difficult to add two reactants with exactly the same number of moles, the limiting reagent is the chemical that determines how far the reaction will go before being used up causing the reaction to stop determined by the calculations of the moles where it has a smaller molar value

Question 7

What are the factors than can affect the percentage yield?

Answer 7

1) the reactants are impure
2) the reaction may involve an equilibrium
3) side reactions occurring
4) some of the product maybe left behind
5) the product maybe difficult to purify

Question 8

How to find the number of moles?

Answer 8

If it was a solid:

Mass/molar mass

If it was a liquid:

Mass (density(g/ml) * volume)/molar mass