Specification Point 3.2:
Describe simple Calorimetry experiments for reactions such as combustion, displacement, dissolving and neutralisation
Calorimetry experiment: Used to measure heat transfer
Calorimetry Experiment for Combustion
The Calorimetry experiment for combustion
- Using a measuring cylinder, put 100 cm3 of water into a copper can
- Measure and record the initial temperature of the water
- Fill the spirit burner with test substance and measure and record its mass
- Place the burner under the copper can and light the wick
- Stir the water constantly with the thermometer and continue heating until the temperature rises by about 20 – 30°c and blow out the flame
- Measure and record the highest temperature of the water
- Measure and record the final mass of burner and remaining alcohol
Rise in temperature of water = final temperature – initial temperature
Mass of alcohol burnt = initial mass – final mass
Q – energy transferred to water
m – mass of water heated
c – the specific heat capacity – is the amount of heat needed to raise the temperature of 1 gram of a substance by 1 oC.
For water, the value is 4.18 J g-1C-1 (joules per gram per degree Celsius).
∆T – change in temperature
When found Q you have calculated amount of heat released when you have burnt the mass of alcohol in the experiment.
You can work out:
Amount of heat released from 1g of substance = Q/mass of substance burnt.
Amount of heat released from 1 mole of substance = Q/mass of substance burnt x molecular weight of substance
Calorimetry Experiment for Displacement, Dissolving and Neutralisation
The Calorimetry experiment for displacement, dissolving and neutralisation
- Using a measuring cylinder, place 25 cm3 of solution 1 into a polystyrene cup
- Measure and record the temperature of solution 1
- Add a measured amount of reactant (solid for dissolving, solution 2 for displacement and Neutralisation) into the Polystyrene cup and stir the mixture
- Measure and record the highest temperature reached by the mixture
Rise in temperature = final temperature – initial temperature
Mass of solution = solution 1 + solution 2 or solution 1 if solid is dissolved
*If water is not used, this is replaced by the mass or volume of other solutions
Example calculations for the above experiment using sample data:
- Temperature of sulphuric acid: 15ºC
- Mass of calcium powder: 5g
- Mass of mixture: 32g
- Highest temperature of mixture: 23ºC
- Change in temperature: 23 – 15 = 8ºC
- Specific heat capacity of H2SO4: 1.34 J g-1 C-1
- Equation: Q = m x c x ΔT
- Q = 32g x 1.34J g-1 C-1 x 8ºC
- Q = 343.04 J
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Jamie got a First class degree in Chemistry from Oxford University before going on to teach chemistry full time as a professional tutor. He’s put together these handy revision notes to match the Edexcel IGCSE Chemistry specification so you can learn exactly what you need to know for your exams.
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