GCSE Science
14th August 1990
- 1Energy Changes
Using the values in the previous question, calculate the overall energy change for the reaction.
- 2Exothermic and Endothermic Reactions
A student heats solid copper carbonate strongly in a test tube, and it breaks down into copper oxide and carbon dioxide. Heating must be continued throughout the reaction for it to keep going. State whether this thermal decomposition reaction is exothermic or endothermic, and explain your reasoning.
- 3Bond Energies, Cells and Fuel Cells
State the only substance produced when a hydrogen fuel cell reacts pure hydrogen with pure oxygen.
- 4Rate and Extent of Chemical Change
A reaction between calcium carbonate and hydrochloric acid produces 72 cm3 of carbon dioxide gas in 30 seconds. Calculate the mean rate of reaction.
- 5Rates of Reaction
Explain how a catalyst increases the rate of a reaction without being used up.
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