Respuesta :
Answer: The percentage yield of aspirin is 38.02 %.
Explanation:
To calculate the number of moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] .....(1)
- For salicylic acid:
Given mass of salicylic acid [tex](C_7H_6O_3)[/tex] = 10.09 g
Molar mass of salicylic acid [tex](C_7H_6O_3)[/tex] = 138.12 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of salicylic acid}=\frac{10.09g}{138.12g/mol}=0.0730mol[/tex]
The chemical equation for the formation of aspirin follows:
[tex]C_7H_6O_3+C_4H_6O_3\rightarrow C_9H_8O_4+CH_3COOH[/tex]
As, acetic anhydride is present in excess. So, it is considered as an excess reagent.
Thus, salicylic acid is a limiting reagent because it limits the formation of products.
By Stoichiometry of the reaction:
1 mole of salicylic acid produces 1 mole of aspirin.
So, 0.0730 moles of salicylic acid will produce = [tex]\frac{1}{1}\times 0.0730=0.0730mol[/tex] of aspirin
Now, calculating the mass of aspirin from equation 1, we get:
Molar mass of aspirin = 180.16 g/mol
Moles of aspirin = 0.073 moles
Putting values in equation 1, we get:
[tex]0.073mol=\frac{\text{Mass of aspirin}}{180.16g/mol}\\\\\text{Mass of aspirin}=13.15g[/tex]
To calculate the percentage yield of aspirin, we use the equation:
[tex]\%\text{ yield}=\frac{\text{Experimental yield}}{\text{Theoretical yield}}\times 100[/tex]
Experimental yield of aspirin = 5.0 g
Theoretical yield of aspirin = 13.15 g
Putting values in above equation, we get:
[tex]\%\text{ yield of aspirin}=\frac{5.0g}{13.15g}\times 100\\\\\% \text{yield of aspirin}=38.02\%[/tex]
Hence, the percent yield of aspirin is 38.01 %.
