Question

For an experiment, a student needs a compound that has the following properties.

• It dissolves in water.
• It is an electrolyte.
• It is excellent conductor of electricity.

Which substance would be the best choice for the experiment?
methanol
acetic acid
distilled water
potassium chloride

Answer 1

The best choice for the experiment from the given options is **potassium chloride (KCl)**.

Here's why:

- **Dissolves in water**: Potassium chloride is highly soluble in water.
- **Electrolyte**: When dissolved in water, KCl dissociates into potassium ions (K⁺) and chloride ions (Cl⁻), making it an electrolyte.
- **Excellent conductor of electricity**: The presence of these ions in solution allows it to conduct electricity very well.

In contrast:
- **Methanol** is a polar solvent but does not dissociate into ions and does not conduct electricity well.
- **Acetic acid** is a weak acid and only partially dissociates in water, making it a weak electrolyte compared to KCl.
- **Distilled water** is a poor conductor of electricity because it has very few ions.

Therefore, potassium chloride is the ideal substance for the student's experiment.