Grade 10 Physical Sciences · Chemical Change

Describe ions and reactions in solution

Explain how ionic solids dissolve in water and why the solution conducts electricity (NaCl(s) → Na⁺(aq) + Cl⁻(aq)).

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Dissolving and Hydration Grade 10Kevinmathscience

How To Write The Dissociation Equations of Ionic CompoundsThe Organic Chemistry Tutor

Identifying Strong Electrolytes, Weak Electrolytes, and Nonelectrolytes - Chemistry ExamplesThe Organic Chemistry Tutor

How to Identify Spectator Ions: Definitions, Examples, & PracticeWayne Breslyn (Dr. B.)

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Question 9.3 · November 2025 · Paper 2 · Provincial · 2 marks

A clean piece of aluminium metal strip is placed in a copper sulphate (

CuSO_{4}

) solution. The reaction was observed again after 2 hours.

After 2 hours it was observed that the blue solution turned colourless and the shiny metallic aluminium turned brown.

The net ionic balanced equation for the reaction is given below:

2 Al (s) + 3 Cu^{2 +} (aq) \to 3 Cu (s) + 2 Al^{3 +} (aq)

9.3 Will the oxidation number of the sulphate ion INCREASE, DECREASE or REMAIN THE SAME during this reaction?

Give a reason for the answer.(2)

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