Question

Give reasons to explain these statements.
(a) Sugar is a pure substance whereas sugar solution is a mixture.
(b) Pure iron cannot be used for construction of buildings.
(c) Decantation cannot be used to separate a mixture of salt and water.
(d) Many people sprinkle water in their courtyard after a sandstorm.

Answer 1

(a) Sugar is pure, as it has only one component, i.e., sugar. Sugar solution is a mixture, as it has sugar and water.
(b) Pure iron cannot be used for the construction of buildings, as it will get rusted.
(c) Salt is soluble in water. Decantation only separates insoluble solids that settle on the bottom; thus, it cannot be used to separate a mixture of salt and water.
(d) Many people sprinkle water in their courtyard after a sandstorm so that the sand particles settle down.