Topic 5 - Measuring Enthalpy Changes

Question 1

how can you measure enthalpy changes?

Answer 1

calorimetry

Question 2

how do you use calorimetry to measure energy transfer in dissolving, displacement and neutralisation reactions?

Answer 2

1. mix the reactants in a polystyrene cup
2. reduce energy loss to the surroundings by putting the cup into a beaker of cotton wool (insulation) and putting a lid on the cup (evaporation)
3. measure the temp in a set timing

Question 3

how do you use calorimetry to measure energy transfer in calorimetry?

Answer 3

1. reduce draughts - use a screen
2. put 50g in a copper can and record the temp
3. weight the spirit burner and the lid
4. put the spirit burner under the can and light the wick. heat the water until the temp is 50 degrees.
5. put out the flame and measure the final temp
6. weigh the spirit burner and the lid again