Is matter around us pure Worksheet-4

Is matter around us pure Worksheet-4

21. A small amount of the sample of a soil was mixed with water in a beaker. After stirring for sometime, the beaker was allowed to stand. The mud was found to settle down. The liquid above the mud was carefully filtered. The filtrate will be :

A. a true solution

B. a colloidal solution

C. can be a true solution or a colloidal solution

D. a suspension

22. Which of the following upon shaking with water will not form a true solution?

A. alum                                           B. common salt

C. albumin                                     D. sucrose

23. Water was taken in four beakers labelled as I to IV. To these beakers, the following substances were added.

Beaker (I) common salt

Beaker (II) Alum

Beaker (III) Potassium nitrate

Beaker (IV) A few drops of Barium chloride and a few drops of dilute H₂SO₄.

After sometime, the contents of the beakers were filtered. The contents of which beaker will leave residue on the filter paper.

A. Beaker (I)                                  B. Beaker (II)

C. Beaker (III)                               D. Beaker (IV)

24. A student mixed a small amount of iron filings and sulphur powder in a dish. He could not affect the separation by simple hand pricking. Which liquid will you suggest to affect the separation ?

A. carbon disulphide                   B. cold water

C. boiling water                            D. kerosene

25. Which of the following will be a heterogeneous mixture?

A. common salt and water         B. cane sugar and water

C. Alum and water                       D. Albumin and water.

26. The correct set of observations for a mixture of iron and sulphur is:

A.

B.

C.

D.

27. When liquid carbon disulphide (CS₂) is added to water taken in a tube, which is the correct observation?

A. I                      B. II                     C. III                   D. IV

28. When a suspension of chalk in water is filtered, which of the following observations is correct?

A. I                      B. II                     C. III                   D. IV

Answer Key:

21. B

Explanation: The filtrate will contain some mud particles and will be a colloidal solution

22. C

Explanation: Albumin is a protein and will form a colloidal solution.

23. D

Explanation: A white residue of Barium sulphate will appear in beaker (iv)

BaCl₂ + H₂SO₄ → BaSO₄ + 2HCl

(White residue)

The contents of fourth beaker will leave residue on filter paper.

24. A

Explanation: Carbon disulphide will dissolve sulphur and not iron filings. The solution formed is filtered to separate iron filings.

25. D

Explanation: Albumin and water will form a heterogeneous mixture.

26. C

Explanation: Iron filings will stick to the magnet while carbon disulphide will dissolve sulphur.

27. A

Explanation: Water and carbon disulphide will form separate layers. Carbon disulphide will form lower layer since it is heavier.

28. C

Explanation: Is the correct observation.