Chemistry 4

 

1. Cement is made hard with

     (a) Dehydration
     (b) Hydration and dissociation of water
     (c) Dissociation of water
     (d) Polymerization

2. Which of the following gases is present under pressure in soft drinks?

     (a) Oxygen
     (b) Nitrogen
     (c) Carbon dioxide
     (d) Nitrous oxide

3. The major harmful gas emitted by automobile vehicle which causes air pollution is

     (a) Carbon monoxide
     (b) Methane
     (c) Carbon dioxide
     (d) Ozone gas

4. Milk tastes sour when kept in the open for sometime due to the formation of

     (a) lactic acid
     (b) citric acid
     (c) acetic acid
     (d) sulphuric acid

5. Which among the following elements is found in maximum percentage in the human body?

     (a) Carbon
     (b) Hydrogen
     (c) Nitrogen
     (d) Oxygen

6. Which of the following is not a precious semiprecious stone?

     (a) Sapphire
     (b) Ruby
     (c) Pearl
     (d) Emerald

7. German silver is an alloy of

     (a) zinc copper and nickel
     (b) silver copper and aluminium
     (c) copper nickel and silver
     (d) zinc silver and copper

8. Which of the following is a natural dye?

     (a) Alizarin
     (b) Aniline blue
     (c) Crystal violet
     (d) Phenolphthalein

9. The presence of ozone in the stratosphere is responsible for

     (a) increasing the average global temperature in recent years
     (b) higher rate of photosynthesis
     (c) checking the penetration of ultraviolet rays to the earth
     (d) supplying oxygen for people travelling in jets

10. The advantage of detergents over soaps is

     (a) Detergents are soluble in water
     (b) Detergents could not give much lather
     (c) Detergents give lather even with hard water
     (d) Soaps give lather with only soft water

11. Formation of ozone hole is maximum over

     (a) Africa
     (b) Antarctica
     (c) Europe
     (d) India

12. Nucleus of an atom consists of

     (a) Proton
     (b) Neutron
     (c) Proton and Neutron
     (d) Electron Proton and Neutron

13. What is “milk of magnesia” chemically?

     (a) Magnesium carbonate
     (b) Sodium bicarbonate
     (c) Calcium hydroxide
     (d) Magnesium hydroxide

14. Bauxite is an alloy of which of the following metals?

     (a) Aluminium
     (b) Silver
     (c) Tin
     (d) Iron

15. Which one of the following metals is used to galvanize iron?

     (a) Copper
     (b) Lead
     (c) Mercury
     (d) Zinc

 

Answer: (1) b (2) c (3) c (4) a (5) d (6) c (7) a (8) a (9) c (10) c (11) b (12) c (13) d (14) a (15) d