Answer the following questions.

1. Which of the following minerals is used in the nuclear reactors?

a) zircon
b) manganese ore
c) mica
d) bauxite

2. Among the following, which is the purest form of iron?

a) steel
b) white cast iron
c) grey cast iron
d) wrought iron

3. Which one of the following forms an irreversible complex with hemoglobin of the blood?

a) carbon monoxide
b) carbon dioxide
c) pure nitrogen gas
d) a mixture of carbon dioxide and helium

4. To galvanise iron, iron is coated with which of the following?

a) aluminium
b) zinc
c) galena
d) silver

5. Which one of the following is an explosive?

a) DDT
b) TNT
c) RDX
d) LSD

6. The presence of which of the following compounds causes temporary hardness of water?

a) calcium bicarbonate
b) sodium bicarbonate
c) magnesium sulphate
d) calcium carbonate

7. Which one of the following is used for bleaching purposes?

a) fluorine
b) chlorine
c) bromine
d) iodine

8. Which gas is present under pressure in soft drinks?

a) oxygen
b) nitrogen
c) carbon dioxide
d) nitrous oxide

9. Starch is a mixture of

a) organic acids
b) amino acids
c) lipids
d) carbohydrates

10. Which one of the following substances undergoes chemical change on heating?

a) sodium chloride
b) silica
c) lead nitrate
d) platinum wire

11. Which of the following is not a metal?

a) iron
b) zinc
c) mercury
d) boron

12. By what name is water which contains soluble salts of calcium and magnesium known?

a) soft water
b) heavy water
c) hard water
d) mineral water

13. Rayon is chemically

a) cellulose
b) glucose
c) amylase
d) pectin

14. Which of the following compound is used in the manufacturing of baking powder?

a) sodium carbonate
b) silicon carbide
c) calcium oxide
d) sodium bicarbonate

15. Marble is a changed form of which of the following?

a) graphite
b) coal
c) limestone
d) basalt

Answers

1. zircon
2. wrought iron
3. carbon monoxide
4. zinc
5. RDX
6. calcium bicarbonate
7. chlorine
8. carbon dioxide
9. carbohydrates
10. lead nitrate
11. boron
12. hard water
13. cellulose
14. sodium bicarbonate
15. limestone