Chemistry 5070 · O Level · Exothermic and endothermic reactions
Exothermic and endothermic reactions — practice question
Respiration is the process that occurs in living cells to release energy.
The overall reaction includes the oxidation of glucose.
$\text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \rightarrow 6\text{CO}_2 + 6\text{H}_2\text{O}$
This reaction is exothermic and is catalysed by enzymes.
(a)[3]
Draw an energy profile diagram for respiration on the axes shown. Add labels for the axes, the enthalpy change, the reactants and the products.
(b)[2]
Explain how a catalyst such as an enzyme can increase the rate of a chemical reaction.
(c)[3]
Respiration, combustion and photosynthesis are key processes in the carbon cycle. Describe how the carbon cycle controls the amount of carbon dioxide in the atmosphere.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Vertical axis: Energy/enthalpy; horizontal axis: Progress of reaction” …