Q4 of 18 Page 9

Answer the following :

State the reasons for hardness in water.

Water is hard due to the minerals dissolved in it. Magnesium and calcium bicarbonates, chlorides and sulphates get dissolved in water which is the main reason for the hardness of water. Hard water does not produce lather when soap is dissolved in it.


More from this chapter

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4

Answer the following :

Name three metals which do not react with water, under normal conditions.

 4

Answer the following :

Name the products formed when the following oxides are dissolved in water. Write a balanced equation.


a. Sulphur dioxide


b. Potassium oxide


c. Carbon dioxide


d. Calcium oxide

 5

Give reasons for the following :

Sodium metal should be stored in kerosene.

 5

Give reasons for the following :

Washing soda loses its crystalline structure quickly.