Calorimetry Lab: Enthalpy Change from a Temperature–Time Graph
Follow the AQA Required Practical 2 method in a virtual calorimeter: record temperatures every 30 seconds, add the reagent at 3 minutes, extrapolate the cooling line back to the time of mixing, and turn ΔT into ΔH with q = mcΔT. Compare a lidded polystyrene cup with a glass beaker to see how heat loss affects the result.
About this simulation
- What
- An interactive Chemistry simulation of Calorimetry Lab: Enthalpy Change from a Temperature–Time Graph.
- Who
- Designed for AP, IB, and A‑Level Chemistry students.
- How
- Runs in any modern browser — drag, adjust, and explore in real time.
Updated 2026-10-02
Key Concepts
q = mcΔT
The heat gained or lost by the solution equals its mass × specific heat capacity × temperature change. Use the mass of the solution, not of any added solid.
From q to ΔH
Divide the heat by the amount of the limiting reagent and reverse the sign: ΔH = −q/n, in kJ mol⁻¹. A temperature rise means a negative (exothermic) ΔH.
Extrapolating the Cooling Curve
Heat escapes while the reaction is still happening, so the highest reading underestimates ΔT. Extending the cooling line back to the time of mixing estimates the temperature change with no heat loss.
Insulation and Error
Heat exchange with the surroundings is the largest error. A lidded polystyrene cup loses heat far more slowly than a glass beaker, giving a result closer to the data-book value.
Exam specification coverage
What This Calorimetry Lab Teaches
Calorimetry measures an enthalpy change by letting a reaction heat or cool a known mass of solution. The temperature change gives the heat transferred through q = mcΔT, and dividing by the amount of the limiting reagent gives ΔH in kJ mol⁻¹. It is AQA A-level Required Practical 2, a core AP Chemistry Unit 6 lab, and the classic 中和反应反应热的测定 experiment.
In this virtual lab you follow the standard method: readings every 30 seconds, the reagent added at 3 minutes with no reading at that instant, and readings continued to 10 minutes. You then fit a straight line to the cooling part of the temperature–time graph and extrapolate it back to the time of mixing to find the corrected temperature change.
Run the same reaction in a lidded polystyrene cup and in a glass beaker. The previous curve stays on the graph in grey, so you can see directly how faster heat loss lowers the peak and steepens the cooling line — and why extrapolation brings the result closer to the data-book value.
Frequently Asked Questions
📚 Read the Guide
Explore the concepts behind this simulation in our detailed article.
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