The electrical conductivity of ionic substances
2 marks · EasyOut of 5 ionic salts, 2 are molten, 1 is in aqueous solution, and the remaining 2 are solid. How many of these salts would you expect to conduct electricity? Show your working.
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3 salts (±0)
Also accept: Three
Common mistakes: Counting solids as conducting.
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Marking points
M1 · 1 mark · Identifies that only molten or aqueous salts conduct electricity.
A1 · 1 mark · Correctly counts: 2 molten + 1 aqueous = 3 will conduct.
Worked solution
Only the 2 molten and the 1 aqueous salt will conduct electricity, because ions are free to move. 2 + 1 = 3 salts.