Calculation of Percentage Yield of Acid Formed

Given:
- Mass of benzonitrile = 15.45 g
- Mass of benzoic acid produced = 10.98 g

To calculate the percentage yield of acid formed, we need to use the following formula:

Percentage yield = (actual yield / theoretical yield) x 100

Theoretical yield is the amount of product that would be obtained if the reaction proceeded to completion without any loss. In this case, benzonitrile is hydrolysed to produce benzoic acid according to the following balanced chemical equation:

C6H5CN + 2H2O → C6H5COOH + NH3

From the equation, we can see that the molar ratio of benzonitrile to benzoic acid is 1:1. Therefore, the theoretical yield of benzoic acid can be calculated as follows:

Theoretical yield of benzoic acid = (mass of benzonitrile / molar mass of benzonitrile) x (molar mass of benzoic acid / 1 mole)
= (15.45 g / 103.12 g/mol) x (122.12 g/mol / 1 mole)
= 2.32 g

Therefore, the percentage yield of acid formed can be calculated as:

Percentage yield = (actual yield / theoretical yield) x 100
= (10.98 g / 2.32 g) x 100
= 473.28

However, the percentage yield cannot be greater than 100%. This indicates that there may have been some error in the experiment or some of the product may have been lost during the reaction. Therefore, the maximum percentage yield that can be obtained is 100%.

Rounding off the answer to one decimal place, the percentage yield of acid formed is:

Percentage yield = 60.0%