Water-A Precious Resource Worksheet-2

Water-A Precious Resource Worksheet-2

1. The freezing point of water is 0 ºC at:

(a) 76 cm of Hg                             (b) 760 cm of Hg

(c) 760 mm of Hg                        (d) 7.6 mm of Hg

2. Which of the following property of icebergs led to the sinking of the famous titanic ship?

(a) Relatively higher density of ice

(b) Only 10 % of the iceberg was above the sea water which couldn’t be seen

(c) Heavy water currents

(d) None of these

3. The solubility of sodium nitrate is:

(a) More than common salt

(b) Less than common salt

(c) Same as that of common salt

4. The rain water dissolves salt from the land and brings them to sea. The concentration of salt in sea water will continue to increase indefinitely. But it has been found that the concentration of salt in sea water is 35 gm per litre of water. Why?

(a) The solubility of salt in water is 36 g per 100 g of water at 20 ºC so it cannot dissolve more than 36 g. The excess salt crystallizes and settle down at the sea floors

(b) The aquatic animals take up the excess salt from the seawater

(c) Salt also gets evaporated along with water so the concentration of salt is maintained

(d) None of these

5. When ice gets converted to water its:

(a) Density remains same

(b) Density decreases till 4ºC

(c) Density increases till 4ºC and then decreases

(d) Density decreases till 4ºC and then Increases

6. When ice gets converted to water its:

(a) Volume remains same

(b) Volume increases till 4ºC

(c) Volume increases till 4ºC and then decreases

(d) Volume decreases till 4ºC and then Increases

7. Which of the following is the best method to cool soft drink bottles?

(a) Keeping them in a deep freezer

(b) Surrounding them with solid carbon dioxide

(c) Surrounding them with ice

(d) None of these

8. We use rubber bottles filled with hot water to warm our beds in winter because:

(a) The heat energy stored in steam is high

(b) Water can absorb in it large amount of heat which it slowly gives out, which keeps the bed warm

(c) Water has low specific heat capacity

(d) All of these

9. Groundwater is an important source for

(a) Drinking                                   (b) Domestic purposes

(c) Industries                                 (d) All of these

10. River water is

(a) Salty             (b) Sour             (c) Fresh            (d) None of these

Answer Key:

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