Expert Chemistry Tutoring

Q1. Knowledge Recall (1 mark)

Define percentage yield.

Q2. Application (2 marks)

Explain why a low percentage yield may be obtained in a chemical reaction.

Q3. Calculations (3 marks)

Calculate the percentage yield of a reaction if the theoretical yield is 100g and the actual yield is 75g.

Q4. Problem Solving (3 marks)

A student wants to prepare 20g of magnesium oxide by reacting magnesium with excess oxygen gas. If the percentage yield is 70%, calculate the mass of magnesium required.

Q5. Knowledge Recall (2 marks)

State one factor that can affect the percentage yield of a reaction.

Q6. Application (2 marks)

Explain how increasing the temperature of a reaction can affect the percentage yield.

Q7. Calculations (4 marks)

A reaction produces 15g of sodium chloride from the reaction of 5g of sodium and excess chlorine gas. Calculate the percentage yield of the reaction if the theoretical yield is 20g.

Q8. Problem Solving (3 marks)

A chemical plant produces 100kg of a product with a percentage yield of 65%. If the theoretical yield is 150kg, calculate the mass of reactants used in the reaction.

Q9. Knowledge Recall (1 mark)

What is the difference between the actual yield and the theoretical yield?

Q10. Application (2 marks)

Explain the importance of obtaining a high percentage yield in industrial processes.