8TH CHANGES AROUND US

NAME

1. Burning of paper is a __________ change

• a) physical
• b) chemical
• c) physical and chemical
• d) neutral

2. Burning of matchstick is an example for chemical reaction caused by _________

• a) contact in physical states
• b) electricity
• c) light
• d) catalyst

3. __________ undergoes rusting

• a) Tin
• b) Sodium
• c) Coppe
• d) Iron

4. The pigment responsible for browning of apples is __________.

• a) hydrated iron (II) oxide
• b) melanin
• c) starch
• d) ozone

5. Brine is a concentrated solution of __________.

• a) sodium sulphate
• b) sodium chloride
• c) calcium chloride
• d) sodium bromide

6) Limestone contains __________ mainly.

• a) calcium chloride
• b) calcium carbonate
• c) calcium nitrate
• d) calcium sulphate

7. Which of the following factor induces electrtolysis?

• a) Heat
• b) Light
• c) Electricity
• d) Catalysis

8. In Haber’s process of producing ammonia __________ is used as a catalyst

• a) nitrogen
• b) hydrogen
• c) iron
• d) nickel

9. Dissolved gases like sulphur dioxide and nitrogen oxides in rain water causes

• a) acid rain
• b) base rain
• c) heavy rain
• d) neutral rain