The electrical conductivity of ionic substances

2 marks · Normal

State the conditions under which sodium chloride, an ionic compound, is able to conduct electricity.

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Sodium chloride conducts electricity when it is molten or dissolved in water (aqueous solution), but not when it is solid.

Also accept: Sodium chloride conducts electricity when it is in the liquid (molten) state or when it is dissolved in water.

Common mistakes: Stating that sodium chloride conducts in all states.; Mentioning electrons instead of ions.

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Marking points

B1 · 1 mark · States 'molten' or 'liquid' state or 'dissolved in water' (aqueous solution).

B2 · 1 mark · States it does not conduct when solid.

Worked solution

Sodium chloride conducts electricity when it is either molten (liquid) or dissolved in water (aqueous), because the ions are free to move. It does not conduct electricity when it is solid.