Chemistry Year 11 - Module 4 - Lesson 2

Calorimetry — Combustion

Use this worksheet after reading the lesson to practise the key ideas and prove you can meet the success criteria.

Name

Date

Class

1. Key Ideas

Jet fuel releases roughly 43,000 kJ per kilogram. Wood releases about 15,000 kJ. That 3× difference isn't guesswork — it's measured in a calorimeter. The principle is simple: burn the fuel, heat water, and watch the thermometer.

The formulas q = mcΔT and ΔH c = −q/n
Why 'm' in q = mcΔT is the mass of water, not fuel

2. Success Criteria

By the end, you should be able to:

The formulas q = mcΔT and ΔH c = −q/n
The components of a spirit burner calorimeter
Five sources of error in combustion calorimetry

3. Key Terms

Negative signThe negative sign in ΔHc = −q/n converts a positive q into the correct negative ΔHc.

Enthalpy change (ΔH)The heat energy exchanged at constant pressure during a reaction.

ExothermicA reaction releasing heat to surroundings (ΔH < 0).

EndothermicA reaction absorbing heat from surroundings (ΔH > 0).

CalorimetryThe experimental measurement of heat changes during chemical processes.

Hess's LawThe total enthalpy change is independent of the pathway taken.

4. Activity: Build the Lesson Map

Use the lesson to complete the table. Keep answers brief but specific.

Prompt	Your answer
Main concept
Important example
Common mistake to avoid
How this links to the next lesson

5. Short Answer Questions

1. Explain this lesson goal in your own words: "The formulas q = mcΔT and ΔH c = −q/n". Use one specific example from the lesson.

Band 32 marks

2. Apply this idea to a new example: "The components of a spirit burner calorimeter". Show your reasoning clearly.

Band 43 marks

3. Analyse why this idea matters for understanding Calorimetry — Combustion: "Five sources of error in combustion calorimetry".

Band 54 marks

6. Extend: Apply the Idea

Band 5/65 marks

A student gives a memorised answer about Calorimetry — Combustion but does not use evidence or reasoning.

Improve the answer by writing a stronger response that uses accurate terminology, a relevant example and a clear explanation.

7. Multiple Choice

1. What is the best first step when answering a question about Calorimetry — Combustion?

A. Identify the key concept being tested

B. Write every fact from memory

C. Ignore the command word

D. Skip examples and evidence

2. Which answer would show stronger understanding of Calorimetry — Combustion?

A. An answer with accurate terms and reasoning

B. A copied definition only

C. A single-word response

D. An answer with no example

3. What should you do if a question asks you to explain?

A. Link the idea to a reason or cause

B. List unrelated facts

C. Only draw a diagram

D. Write the shortest possible answer

8. Success Criteria Proof

Finish with evidence that you can do each success criterion.

Success criterion 1

Prove that you can: The formulas q = mcΔT and ΔH c = −q/n