Is matter around us pure Worksheet-5
A. Simple distillation B. Steam distillation
C. Fractional distillation D. Any of these
A. Distillation B. Evaporation
C. Centrifugation D. Sublimation
(a) Ice (b) Milk (c) Iron (d) Hydrochloric acid (e) Calcium oxide (f) Mercury (g) Brick (h) Wood (i) Air.
A. (a), (c), (e), (f) B. (a), (d), (e), (f), (c)
C. (a), (h), (d), (f) D. (a), (d), (g), (f), (c)
(a) Sodium chloride solution (b) Milk (c) Copper sulphate solution(d) Starch sol
A. (a), (c), (d) B. (b), (d)
C. (a), (b), (d) D. (c), (d)
A. By heating the solution
B. By cooling the solution
C. By increasing the amount of solute
D. By centrifugation of the solution
A. Particles of dispersed phase combine with the particles of dispersion medium so they do not combine with each other.
B. Dispersion medium forms a layer between the particles of dispersed phase so they do not combine with one another
C. Due to the presence of similar charge on the dispersed phase particles they repel each other
Explanation: By simple distillation. Vapours of the liquid which has low boiling point will be formed first and collected. The liquid having higher boiling point will remain in the vessel.
Explanation: Butter is separated from curd by centrifugation.
Explanation: Salt from sea water is obtained by evaporation.
Explanation: Camphor sublimes hence camphor is separated from salt by sublimation.
Explanation: Pure substances in the given list of materials are :
(a) Ice (compound) (c) Iron (element) (e) Calcium oxide (compound) (f) Mercury (element).
Both milk and hydrochloric acid are homogeneous mixtures.
Hydrochloric acid is formed by passing the vapours of hydrogen chloride gas through water.
Explanation: Milk and starch are colloidal solution hence they show Tyndall effect.
Sodium chloride solution and copper sulphate solution are true solutions hence they do not show Tyndall effect.
Explanation: A saturated solution can be made unsaturated by increasing the temperature of solution by heating it or by increasing the amount of solvent in the solution i.e. diluting it.
Explanation: Similar charge (positive / negative) is present on the particles of dispersed phase. For example iron sol particles have positive charge due to which they repel each other.