Gradegorilla Chemistry

Chemistry µGCSE:
Energy Changes

10 quick questions - for GCSE and iGCSE

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10 minutes maximum! (can you do it in 5?)

1. Chemical reactions in which heat energy is given out are described as …..

2. The table below gives information about the temperature changes in 3 reactions:

The reactions which are exothermic are:

3. Which of the following types of chemical reactions are always endothermic ?

Q4-6 refer to the following reaction profile:

Energy changes in a reaction

4. This diagram represents the reaction profile for an …

A. exothermic reaction as the products are at a lower energy level than the reactants.
B. exothermic reaction as the products are at a higher energy level than the reactants.
C. endothermic reaction as the products are at a lower energy level than the reactants.
D. endothermic reaction as the products are at a higher energy level than the reactants.

5. The enthalpy change (energy change) for this reaction is correctly labelled by line .

6. Line D represents ….

Q7 – 10. Water at 25 °C was used to dissolve ammonium nitrate (NH₄NO₃).

The ammonium nitrate disappeared and a temperature of 21°C was recorded immediately afterwards.

The student used a polystyrene cup to carry out this experiment as shown here.

7. The reason for using a polystyrene cup rather than a beaker is that a polystyrene cup is…..

8. The student correctly concluded that the dissolving of ammonium nitrate was …

9. Which of the following energy level diagrams correctly represents this reaction?

energy change diagrams x4

10. Estimate the temperature of the solution if the volume of water was halved but the same mass of ammonium nitrate used.