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Topic: Thermochemistry
Level: OL/HL
Exam Focus: Section A Practical Skills
1. Experiment Snapshot
Feature
Details
Experiment
Heat of Neutralisation
Exam Importance
⭐⭐⭐⭐ Practical exam standard
Typical Marks
5–15 marks
2. Aim
To measure the heat change when an acid neutralises a base.
3. Quick Theory
Neutralisation is usually exothermic. The temperature rise is used to calculate heat released using Q = mcΔT.
Examiner Tip: Always connect the observation or reading to the purpose of the experiment.
4. Apparatus and Chemicals
Apparatus
Chemicals
Polystyrene cup, thermometer, measuring cylinders, beaker and lid.
Acid solution and alkali solution.
Safety: Wear goggles and follow teacher instructions, especially with acids, alkalis, hot apparatus and oxidising agents.
5. Step-by-Step Procedure
Measure equal volumes of acid and alkali.
Record their initial temperatures.
Mix the solutions in an insulated cup.
Stir and record the maximum temperature.
Calculate the temperature change.
Use Q = mcΔT.
6. Observations / Results
Situation
Expected Result
Temperature
Increases.
Reaction type
Exothermic.
7. Student Common Mistakes
Using final temperature instead of temperature change.
Ignoring heat loss to surroundings.
Using the wrong mass of solution.
Forgetting that exothermic enthalpy changes are negative.
8. Examiner Traps
Trap: Students often describe the apparatus but forget the exact observation, reading, or endpoint. Use precise words.
8A. Labelled Diagram
Here the important idea is heat change, not a visible product. The insulated cup helps keep heat in so the temperature rise is easier to measure accurately.
Heat of Neutralisation
The insulation reduces heat loss so the temperature change is more reliable.
Teacher Voice: Encourage students to say that the reaction is exothermic and that the temperature change is what gets used in the calculation.
9. 🎮 Interactive Simulator
Try It Yourself
Which value is used in Q = mcΔT?
Neutralisation is usually:
Result Window
Ready
Choose the correct actions to complete the practical.
Score:0/0
10. Past Paper Style Questions
State the aim of this experiment. [2]
Describe the procedure in order. [4]
State one safety precaution. [2]
State one common error and one improvement. [4]
Explain the key observation/result. [3]
11. Mark Scheme
Aim correct [2]. Procedure in correct order [4]. Safety precaution [2]. Error and improvement [4]. Observation/result explained [3].