Separation of substances Worksheet-1

Separation of substances Worksheet-1

Fill in the blanks:

1. When two or more pure substances are mixed together in such a way that each component retains its properties is called a ______.
2. ______ method of separation is based on the property that grains are heavier than husk and hay.
3. A solution in which no more solute can be dissolved at a fixed temperature is called a _____.
4. Formation of dew in nature is due to ______ of moisture in the air.
5. In lemon water, lemon juice is a ______. (solute/solvent)

Multiple-Choice Question:

6. In a flour mill, impurities like husk and stones are removed from wheat before grinding it by:

(A) Threshing      (B) Winnowing    (C) Sieving           (D) Hand-picking

7. Common salt is obtained from:

(A) sea water       (B) river water     (C) lake water     (D) spring water

8. Salt can be obtained from sea water by:

(A) filtration                                      (B) decantation  

(C) Centrifugation                            (D) Evaporation

9. Mixtures are:

(A) impure substances                   (B) pure substances

(C) Molecules                                   (D) none of these

10. Fractional distillation is used to separate:

(A) solids from solids                       (B) solids from liquids

(C) liquids from liquids                   (D) none of these

11. A pure substance is made up of:

(A) Only one kind of molecules     (B) Two or more kinds of molecules

(C) Different types of molecules    (D) None of these

12. Brass is a mixture of ________and ________.

(A) Copper, Zinc  (B) Copper, tin    (C) Copper, iron  (D) Copper, Chromium

Answer key:

1. Mixture
2. Winnowing
3. saturated solution
4. Condensation
5. Solute
6. (C)
7. (A)
8. (D)
9. (A)
10. (C)
11. (A)
12. (A)