Which of the following is NOT a reason why the actual yield is less than the theoretical yield in a chemical reaction?

• A. All reactants are pure and react completely as predicted
• B. Loss of product during purification or transfer
• C. Incomplete reactions where not all reactants are converted to products
• D. Side reactions that produce undesired products

Answer: (A)

Verified step by step guidance

1. Understand the concept of theoretical yield: it is the maximum amount of product that can be formed from given amounts of reactants, assuming complete reaction with no losses.
2. Recognize that actual yield is often less than theoretical yield due to practical factors such as loss of product during purification or transfer, incomplete reactions, and side reactions producing undesired products.
3. Analyze each option to determine if it would cause the actual yield to be less than the theoretical yield.
4. Note that 'All reactants are pure and react completely as predicted' implies an ideal scenario with no losses or side reactions, so it would not cause the actual yield to be less than the theoretical yield.
5. Conclude that the option stating 'All reactants are pure and react completely as predicted' is NOT a reason for actual yield being less than theoretical yield.