Grade 8

Mixtures

A. Multiple Choice Questions – Only write down the letter corresponding to the correct answer.

  1. A mixture of sand and table salt is separated by means of the filtration method. The substance that remains in the filter paper after the filtration has taken place is called the

A. residue

B. filtrate

C. solution

D. distillate

2.  A mixture of the following two substances could be separated by making use of the difference between their densities and that of water:

A. sugar and salt

B. iron filings and lead shot

C. alcohol and ether

D. copper filings and saw dust

3.  To obtain pure water from salt water the following apparatus should be used:

A. a distilling flask, bunsen burner and a Liebig condenser

B. a separating funnel and a Liebig condenser

C. a funnel and filter paper

D. a separating funnel, bunsen burner and a Liebig condenser

4.  Air is a ......

A. compound

B. element

C. mixture of compounds

D. mixture of compounds and elements

5.  A mixture of sugar and water can be separated by means of ...

A. filtration

B. a separating funnel

C. distillation

D. a magnet

6.  To separate a mixture by filtration, ...

A. both substances should be solids

B. the substances should form a solution

C. one of the substances should have a high density

D. both substances should be liquids

7.  Which of the following can be separated by a separating funnel?

A. miscible liquids with different densities

B. immiscible liquids with different densities

C. miscible liquids with different boiling points

D. immiscible liquids with different boiling points

8.  Which one of the following is never used during fractional distillation?

A. a separating funnel

B. a Bunsen burner

C. a Liebig condenser

D. water (8 X 3 = 24)

B. Choose from column B the separation method which is most suitable to separate a substance in column A. An item in column B may be chosen more than once.

Column A Column B

  1. water and olive oil A. magnet
  2. water and table salt B. hand sorting
  3. fuels in crude oil C. filtration with water as solvent
  4. nuts and rice D. separating funnel
  5. purification of sea water E. heating strongly

6. sulphur and iron filings F. distillation

7. water and alcohol G. fractional distillation (14)

C. Make neat sketches of the each of the following apparatus and explain briefly for what each of these is used:

1. a separating funnel

2. a distilling flask

3. a Liebig condenser (12)

TOTAL : 50 MARKS


ANSWER SHEET

NAME:

SECTION A

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7.

8.

SECTION B

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7.

SECTION C

1. 2.

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