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WalesCombined Science

Unit 5 Chemistry 2: Acids, metals and energy

5 dot points across 5 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

What are acids and bases, and what does the pH scale tell us?

Acids, bases and alkalis, the pH scale and indicators, and neutralisation as a reaction between an acid and a base.
A focused answer to the WJEC GCSE Science Double Award Unit 5 topic on acids and bases, covering acids, bases and alkalis, the pH scale and indicators, and neutralisation as the reaction between an acid and a base.
9 min answer →

What is electrolysis, and how is it used to extract aluminium?

Electrolysis as the breakdown of an ionic compound using electricity, the products at the electrodes, and the extraction of aluminium.
A focused answer to the WJEC GCSE Science Double Award Unit 5 topic on electrolysis, covering the breakdown of molten and dissolved ionic compounds using electricity, the products formed at each electrode, and the extraction of aluminium.
9 min answer →

What are exothermic and endothermic reactions, and how are they shown on a reaction profile?

Exothermic and endothermic reactions, examples of each, and reaction profile diagrams showing activation energy.
A focused answer to the WJEC GCSE Science Double Award Unit 5 topic on energy changes, covering exothermic and endothermic reactions with examples, and reaction profile diagrams showing the energy change and activation energy.
9 min answer →

What do acids react with, and how is a soluble salt prepared?

The reactions of acids with metals, bases and carbonates, the salts produced, and how to prepare a soluble salt.
A focused answer to the WJEC GCSE Science Double Award Unit 5 topic on the reactions of acids, covering reactions with metals, bases and carbonates, the salts produced, and the method for preparing a soluble salt.
9 min answer →

How are metals ordered by reactivity, and how does this decide how a metal is extracted?

The reactivity series, displacement reactions, and how the method of extracting a metal depends on its reactivity.
A focused answer to the WJEC GCSE Science Double Award Unit 5 topic on metals, covering the reactivity series, displacement reactions, and how the method of extracting a metal depends on its position in the reactivity series.
9 min answer →