MCQ Questions: Separation of Substances - Grade 7 MCQ

Pebbles and stones are removed from sand by sieving. Sieving allows the fine flour particles to pass through the holes of the sieve while the bigger impurities remain on the sieve

Churning is the process used to separate butter from milk or curd. This involves rapidly stirring the milk or curd to separate the butterfat from the liquid.

The best method for separating a mixture of sugar and water is evaporation.

Here's why:

• Decantation: This method is used to separate a liquid from a solid that has settled at the bottom. It is not suitable for separating sugar from water.
• Filtration: This method separates solids from liquids or gases. Since sugar dissolves in water, it cannot be filtered out.
• Evaporation: This method involves heating the solution to evaporate the water, leaving behind the sugar. It is effective for separating a dissolved solid from a liquid.
• Sedimentation: This method is used to separate solid particles that settle at the bottom of a liquid. Since sugar is dissolved in water, it does not settle out.