Water

Question 1

Freezing point

Answer 1

0°C

Question 2

Boiling point

Answer 2

100°C

Question 3

Ice is less dense than water

Answer 3

Floats on water

Question 4

Water is an excellent solvent

Answer 4

Many substances dissolve in it

Question 5

Water treatment

Answer 5

1. Screening
2. Settling
3. Filtration
4. Chlorination
5. Fluoridation

Question 6

Hard water

Answer 6

Is water that does not easily form a lather with soap

Question 7

Soft water

Answer 7

Is water that forms a lather easily with soap

Question 8

Hardness in water is caused by the presence of

Answer 8

Calcium ions dissolved in the water

Question 9

Hardness can be removed

Answer 9

By passing the water through an ion exchange resin, or by distillation

Question 10

Ion exchange resin

Answer 10

Exchanges calcium ions for hydrogen ions to remove hardness

Question 11

Electrolysis

Answer 11

water can be broken into its elements hydrogen and oxygen, is the production of a chemical reaction

Question 12

Hoffman voltameter

Answer 12

Is used in the electrolysis of water to form H2 and O2

Question 13

Twice as much hydrogen as oxygen is formed

Answer 13

Because water is h2O

Question 14

To test various water samples for hardness

Answer 14

Soap solution

Question 15

Blue cobalt chloride paper is used to test

Answer 15

For water