What would happen with non-electrolytes?
3 marks · EasyA student tests three substances for their ability to conduct electricity when solid and when dissolved in water. The results are shown in the table.
| Substance | Conducts as a solid? | Conducts dissolved in water? |
|---|---|---|
| A (potassium bromide) | No | Yes |
| B (ethanol) | No | No |
| C (magnesium) | Yes | n/a |
Identify substances A, B, and C as ionic, covalent, or metallic.
Which substance is a non-electrolyte?
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) A: ionic, B: covalent, C: metallic · must show A-ionic, B-covalent, C-metallic
(b) B (ethanol) · must show identifies B/ethanol as non-electrolyte
Show mark scheme and worked solution
Marking points
B1 (a) · 2 marks · Correctly classifies all three: A as ionic, B as covalent, C as metallic (must have all right for 2 marks; one error max, award 1).
B1 (b) · 1 mark · Identifies B (ethanol) as the non-electrolyte.
Worked solution
a) A is ionic (does not conduct as solid, does in solution); B is covalent (never conducts, is a non-electrolyte); C is metallic (conducts as solid).
b) B (ethanol) is the non-electrolyte.