9.21 g of toluene (92.14 g/mol) reacts with chlorine in sunlight to give benzal chloride (161.03…

Step 1. $n = \dfrac{9.21\ \text{g}}{92.14\ \text{g/mol}} = 0.100\ \text{mol} = 100\ \text{mmol}$.

Step 2. Benzal chloride: $0.100\ \text{mol} \times 0.85 \times 161.03\ \text{g/mol} = 13.7\ \text{g}$.

Step 3. Benzaldehyde: $0.100\ \text{mol} \times 0.85 \times 0.90 \times 106.12\ \text{g/mol} = 8.11\ \text{g}$.

Step 4. Overall yield $= 0.85 \times 0.90 = 0.765$, which is $76.5\ \%$.