Question

$\underset{\left(138.12gmo{l}^{-1}\right)}{\underset{Salicylicacid}{C_7{H}_6{O}_3}}+\underset{\left(102.09gmo{l}^{-1}\right)}{\underset{Aceticanhydride}{C_4{H}_6{O}_3}}\to \underset{\left(180.15gmo{l}^{-1}\right)}{\underset{Aspirin}{C_9{H}_8{O}_4}}+\underset{\left(60.05gmo{l}^{-1}\right)}{\underset{aceticacid}{C_2{H}_4{O}_2}}$
What is the percentage yield if 0.85 g of aspirin formed in St reaction of .1 g of salicylic acid with excess of acetic anhydride ?

• A. 65%
• B. 77%
• C. 85%
• D. 91%

Answer 1

The correct option is A 65%

Mass of aspirin (theoretical) formed from $1g$ of salicylic acid is:

$=\frac{180.15}{138.12}=1.304g$
% yield $=\frac{Actualamountofproduct}{Theoreticalamountofproduct}\times 100$

By substituting the values we get:

$=\frac{0.85}{1.304}\times 100\approx 65$ %