The newest 11 of 11 written questions. Open one to see it on the real paper.
The student repeats the experiment at a higher temperature. The reaction is faster. Explain why, using collision theory.
See it on the paper →The reaction between magnesium and dilute hydrochloric acid is exothermic. Fig. 6.1 shows the reaction pathway diagram for the reaction. A energy reactants B C reaction progress Fig. 6.1 Complete the labels, A, B and C, on Fig. 6.1.
See it on the paper →The reaction between calcium carbonate and dilute hydrochloric acid is exothermic. Complete Fig. 5.3 to show an energy level diagram for an exothermic reaction. energy Label the activation energy and the energy change on your diagram. reactants Fig. 5.3 progress of reaction
See it on the paper →The reaction between magnesium and dilute hydrochloric acid is an exothermic reaction. Use the axes shown in Fig. 8.2 to draw and label the energy level diagram for this reaction. Label: • • • the energy of the reactants and the products the energy change in the reaction the activation energy of the reaction. energy pr...
See it on the paper →Explain how Fig. 11.2 shows that energy is given out.
See it on the paper →Use the axes shown in Fig. 2.1 to draw and label the energy level diagram for this reaction. Label: • the energy of the reactants and the products • the energy change in the reaction • the activation energy of the reaction. energy progress of reaction Fig. 2.1
See it on the paper →Use Fig. 2.3 to calculate the energy given out in the reaction. energy given out = kJ
See it on the paper →The reaction in stage 2 of the Contact process is exothermic. Fig. 11.1 shows the energy level diagram for the reaction. Complete the labels on Fig. 11.1. Choose the labels from the list. energy given out energy taken in products reactants reactants have less energy energy progress of reaction Fig. 11.1
See it on the paper →Ethane burns in oxygen to make carbon dioxide and water. The balanced symbol equation is shown. 2C 2 H 6 + 7O 2 4CO 2 + 6H 2 O The reaction is exothermic. Use the axes shown in Fig. 8.1 to draw and label the energy level diagram for this reaction. Label: • • • the energy of the reactants and the products the energy cha...
See it on the paper →Explain how the energy level diagram shows that the reaction is exothermic.
See it on the paper →Which graph shows how the temperature changes as the acid is being added to the alkali?
See it on the paper →Most candidates gained at least partial credit. Many discussed molecules gaining energy rather than kinetic energy or more collisions rather than more of the collisions being successful.
— Examiner report, May/June 2025, 0654/43 Q8(d) (Cambridge)
Activation energy and products were often labelled correctly. Occasionally the energy change was incorrectly labelled as heat loss.
— Examiner report, February/March 2025, 0654/42 Q6(d) (Cambridge)
There were some good energy level diagrams. Those who drew the correct profile for an exothermic reaction normally correctly labelled the reactants, products and activation energy. A few candidates drew the energy level diagram for an endothermic reaction. A frequent error was to see the energy change arrow going the full height of the curve. Candidates should be encouraged to be more accurate whe...
— Examiner report, May/June 2023, 0654/41 Q8(c) (Cambridge)
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