SEPARATION OF SUBSTANCES

Filtration is a method to separate the components of a

• (a) solution

• b) mixture of a liquid and an insoluble substance

• (c) both (a) and (b)

• (d) pure substance

Threshing is done by

• (a) beating

• (b) bullocks

• (c) machines

• (d) all of these

Which method is used to separate pebbles and stones from sand?

• (a) Handpicking

• (b) Winnowing

• (c) Sieving

• (d) Any of these

The property which forms the basis of sieving

• (a) difference in weight

• (b) difference in colour

• (c) difference in shape

• (d) difference in size

Mixtures need to be separated because

• (a) to remove undesirable substances

• (b) to get desirable substances

• (c) to obtain highly pure substances

• (d) all of the above

A solid is dissolved in water. Which one of the following methods can be used to separate it?

• (a) Filtration

• (b) Decantation

• (c) Distillation

• (d) Evaporation

Which of the following method is used when there is a difference in size and colour of desirable and undesirable constituents?

• (a) Handpicking

• (b) Threshing

• (c) Filtration

• (d) Decantation

At water treatment plants, the river water is filtered by using

• (a) filter paper

• (b) porcelain filters

• (c) cloth filters

• (d) sand filters

When no more salt dissolves in water at a particular temperature, then the solution at that temperature is called

• (a) unsaturated

• (b) saturated

• (c) supersaturated

• (d) none of these

Distillation is a method of obtaining pure …………….. from a solution.

• (a) liquid

• (b) solid

• (c) gas

• (d) all of them