(a) When a saturated solution of potassium chloride prepared at 60°C is allowed to cool at room temperature, crystals of potassium chloride will be formed.
(b) Initially, sugar will be obtained as water will get evaporated. But on dry heating sugar gets charred and it turns black.
(c) The black coloured compound, iron sulphide is formed when a mixture of iron filings and sulphur powder is heated strongly.