Class 8 C D E , ( Some useful Chemicals)

What part of earth is covered by water?

• 71%

• 25%

• 33%

• 73%

Water that produces lather with soap easily is called?

• Hard Water

• Soft Water

Water that contains calcium bicarbonate and Magnesium bicarbonate dissolved in it is called

• Permanent hard water

• Temporary hard water

Water that contains chlorides and sulphates of calcium and magnesium dissolved in it is called

• Permanent hardwater

• Temporary hardwater

Which type of hard water can be removed by boiling?

• Temporary hard water

• Permanent hard water

Permanent hard water can be removed by

• Boiling

• by treating with sodium carbonate ( washing soda)

Washing soda is also called

(a)  

Na₂co₃ is the molecular formula of

• Sodium Carbonate

• Sodium Bicarbonate

Baking Soda is also called

(a)  

Glycerol is commonly called

• Glycerin

• Propane