| 1. | Which of the following is a conductor of electricity |
A. rubber | |
B. pure water | |
C. salt water | |
D. Benzene |
| 2. | How can pure water be obtained from sea water? |
A. by distillation | |
B. by condensation | |
C. by evaporation | |
D. by Prabhaji Aswan |
| 3. | Sea water is more salty than rain water because |
A. Rivers bring salts with them | |
B. there are salt rocks in the sea | |
C. The atmosphere around the ocean is salty | |
D. animals living in the sea produce salt |
| 4. | The temporary hardness of water is due to |
A. bicarbonates of Ca and Mg | |
B. Carbonates of Ca and Mg | |
C. Chlorides of Ca and Mg | |
D. Sulphates of Ca and Mg |
| 5. | Permanent hardness in water is due to the presence of? |
A. sulfates of sodium and potassium | |
B. sulfates of magnesium and calcium | |
C. carbonates of sodium and magnesium | |
D. bicarbonates of magnesium and calcium |
| 6. | On boiling of water in the kettle, a layer of white material gets deposited on its inner layer, that layer is – |
A. of sodium chloride | |
B. of calcium chloride | |
C. of magnesium chloride | |
D. of carbonates of Ca and Mg |
| 7. | What is the function of heavy water in a nuclear reactor? |
A. slowing down neutrons | |
B. speed up neutrons | |
C. reactor cooling | |
D. stop nuclear reaction |
| 8. | Heavy water is used as a coolant in nuclear reactors. heavy water |
A. mineral rich water | |
B. ozonized water is | |
C. Water containing heavy metal minerals is | |
D. Water containing heavy isotopes of hydrogen is |
| 9. | What is the chemical composition of ‘heavy water’ (Guru Jal)? |
A. H₂O₂ | |
B. H₂O | |
C. HDO | |
D. D₂O |
| 10. | heavy water molecular weight is |
A. 18 | |
B. 20 | |
C. 22 | |
D. 24 |