Required Practical: Investigating Temperature Changes Flashcards
All 6 cards in this deck
What are the steps to measure the temperature change of a neutralisation reaction?
e.g. cm of acid added to cm of alkali
- Measure cm of alkali into a polystyrene cup with a lid and record its temperature.
- Add cm of acid, stir, and record the highest temperature reached.
- Temperature change = highest temperature − starting temperature.
Why does a polystyrene cup give more accurate results than a glass beaker in a temperature-change investigation?
Polystyrene is a better thermal insulator, so there is less energy transfer to the surroundings.
True or false? Repeating a temperature-change experiment in a metal container instead of a polystyrene cup gives a smaller temperature change.
True. Metal is a better conductor, so more energy is transferred to (or absorbed from) the surroundings.
Give the independent and dependent variables in this investigation.
e.g. different masses of zinc powder added to copper sulfate solution
Independent: mass of zinc added.
Dependent: highest temperature reached (or temperature change).On a graph of highest temperature against mass of solid added, where do you read the initial temperature of the reaction mixture?
Where the line of best fit, extrapolated back, meets the -axis.
On a temperature against mass graph, what does the point where the temperature stops changing show?
The reaction is complete — one reactant has been used up and the added solid is now in excess, so no further reaction occurs.