Question

5.3 g of benzaldehyde was reacted with an excess of acetophenone to produce 5.2 g of the enone product as per the reaction shown below. The yield of the reaction is ................ %. (Round off to the nearest integer) 

Hint:

To calculate the percent yield, use the formula \(\text{Percent yield} = \frac{\text{Actual yield}}{\text{Theoretical yield}} \times 100\).

Answer 1

Correct Answer: 50

Step 1: Calculate the moles of benzaldehyde.
The molecular weight of benzaldehyde (MW = 106 g/mol) is given, so the moles of benzaldehyde is: \[ \text{Moles of benzaldehyde} = \frac{5.3 \, \text{g}}{106 \, \text{g/mol}} = 0.05 \, \text{mol} \] Step 2: Calculate the theoretical yield.
Assuming a 1:1 molar ratio of benzaldehyde to product, the theoretical yield is: \[ \text{Theoretical yield} = 0.05 \, \text{mol} \times 208 \, \text{g/mol} = 10.4 \, \text{g} \] Step 3: Calculate the actual yield.
The actual yield is 5.2 g, so the percent yield is: \[ \text{Percent yield} = \frac{5.2}{10.4} \times 100 = 50% \] Thus, the yield of the reaction is 98%.