Physical and Chemical Changes Worksheet-1

Physical and Chemical Changes Worksheet-1

1. The compound formed on burning magnesium ribbon is:

(a) Magnesium hydroxide          (b) Magnesium oxide

(c) Any of these                             (d) Magnesium carbonate

2. The compound formed on dissolving magnesium oxide in water is:

(a) Magnesium hydroxide          (b) Magnesium oxide

(c) Magnesium carbonate          (d) Any of these

3. Which of the following property remains same during physical as well as chemical changes?

(a) Density                                     (b) Shape

(c) Mass                                          (d) Arrangement of particle

4. Silver when exposed to air turns black due to:

(a) Change of form                      (b) Chemical change

(c) Change of state                       (d) Physical change

5. What is the best method to prevent rusting?

(a) Painting                                    (b) Greasing

(c) Galvanization                          (d) Precipitation

6. Add a small amount of impure alum powder to the water and stir with the glass rod. When it gets dissolved add more alum powder and continue doing so till alum stops dissolving in the water:

What is the process which takes place is going from state (iii) to (iv)?

(a) Crystallization                        (b) Loading

(c) Substitution                            (d) None of these

7. Match both the columns and mark the correct option from the codes given below:

Column I            -       Column II

(A) Limestone      -      (I) NaHCO₃

(B) Blue vitriol      -     (II) CuSO₄

(C) Vinegar            -     (III) CaCO₃

(D) Baking soda    -     (IV) CH₃COOH

(a) A → (III); B → (II); C → (IV); D → (I)

(b) A → (I); B → (II); C → (IV); D → (III)

(c) A → (II); B → (III); C → (I); D → (IV)

(d) A → (IV); B → (I); C → (II); D → (III)

8. Acetic acid + Sodium hydrogen carbonate → (i)  + Ca(OH)₂ → (ii) + Water

What could (i) and (ii) be?

(a) (i): CaCO_{3 ,} (ii) CO₂               (b) (i): H₂O; (ii) CaCO₃

(c) (i): CO₂; (ii) CaCO₃               (d) (i): H₂O; (ii) CO₂

9. A chemical reaction in which heat is given out is called

(a) Exothermic reaction             (b) Endothermic reaction

(c) Decomposition reaction       (d) Neutralization reaction

10. A physical change is named so because

(a) Only change in physical properties takes place

(b) Energy transfer takes place

(c) It is reversible

(d) All of these

Answer Key:

1. (b)
2. (a)
3. (c)
4. (b)
5. (c)
6. (a)
7. (a)
8. (c)
9. (a)
10. (a)