Daily Practice

GCSE Science

20th November 1990

5 questions · GCSE · 584 questions in this band

1
Reactivity, Acids and Salts
Why is aluminium extracted by electrolysis rather than by reduction with carbon?
2
Electrolysis
In the industrial extraction of aluminium, explain why the aluminium oxide is dissolved in molten cryolite rather than melted on its own.
3
Energy Changes
Using the values in the previous question, calculate the overall energy change for the reaction.
4
Exothermic and Endothermic Reactions
Explain, in terms of the reaction pathway, why adding a catalyst increases the rate of a reaction without changing the overall energy change of the reaction.
5
Bond Energies, Cells and Fuel Cells
State whether breaking a chemical bond requires energy or releases energy.

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