Question

Consider the above reaction where 6.1 g of Benzoic acid is used to get 7.8 g of m-bromo benzoic acid. The percentage yield of the product is _________. (Round off to the Nearest Integer). [Given : Atomic masses : C : 12.0 u, H : 1.0 u, O : 16.0 u, Br : 80.0 u]

Hint:

Percentage yield is (Actual Mass / Theoretical Mass) $\times$ 100.

Answer 1

Correct Answer: 78

Step 1: Molar mass of Benzoic acid ($C_7H_6O_2$) = 122 g/mol. Molar mass of m-bromobenzoic acid ($C_7H_5O_2Br$) = 201 g/mol.
Step 2: Theoretical yield: $\frac{6.1}{122} \times 201 = 0.05 \times 201 = 10.05 \text{ g}$.
Step 3: % Yield $= \frac{7.8}{10.05} \times 100 \approx 77.61%$. Rounding to 78.