Some Commonly used Salts

Some Commonly used Salts

Baking Soda

» Used for cooking of certain foods for making baking powder (a mixture of sodium hydrogen carbonate and tartaric acid).
» On heating during baking, baking soda gives off carbon dioxide. It is this carbon dioxide that raises the dough. The sodium carbonate produced on heating the baking soda gives a bitter taste. Therefore, instead of using the baking soda alone, baking powder is used.
» In medicines, being a mild and non-corrosive base, baking soda is used in medicines to neutralize the excessive acid in the stomach and provide relief.
» In soda acid fire extinguishers.

Washing Soda

» Washing soda is sodium carbonate dehydrate, Na₂CO₃.10H₂O
» It is used in the manufacture of caustic soda, glass, soap powders, borex, and in paper industry.
» It is used for removing permanent hardness of water.
» It is used as a cleansing agent for domestic purpose.

Plaster of Paris

Chemically, it is 2CaSO₄.H₂O or CaSO₄.l/2 H₂O
It is used :
1. in making casts for manufacture of toys and statues.
2. in medicine for making plaster casts to hold fractured bones in place while they set. It is also used for making casts in dentistry.
3. for making the surface of walls and ceiling smooth.
4. for making decorative designs on ceilings, walls, and pillars.
5. for making ‘chalk’ for writing on blackboard.
6. for making fire-proof materials.

Bleaching Powder

Chemically, it is calcium oxychloride, CaOCl₂
It is used :
1. in textile industry for bleaching of cotton and linen.
2. in paper industry for bleaching of wood pulp.
3. in making wool unshrinkable.
4. as disinfectant and germicide for sterilization of water.
5. for the manufacture of chloroform.
6. as an oxidizing agent in chemical industry.

Copper Sulphate

Copper sulphate is white when it is anhydrous and blue in colour when associated with water of crystallisation CuSO₄.5H₂O. It is used to test the presence of water.

Lime

It is chemically calcium oxide (CaO) and also called quicklime. Excessive use of fertilizers makes the soil more acidic; to neutralise it, quicklime is added to soil as acidic soil is not good for growth of the plant.

Potassium Nitrate

It is used as fertilizer, in gun powder (C⁺ S⁺ KNO₃).

Magnesium Hydroxide

It is used as a remedy for hyper-acidity in stomach.