Describe the importance of the following: (i) limestone (ii) cement (iii) plaster of paris.

(i) Chemically, limestone is CaCO₃.

Importance of limestone

(a) It is used in the preparation of lime and cement.

(b) It is used as a flux during the smelting of iron ores.

(ii) Chemically, cement is a mixture of calcium silicate and calcium aluminate.

Importance of cement

(a) It is used in plastering and in construction of bridges.

(b) It is used in concrete.

(iii) Chemically, plaster of Paris is 2CaSO₄.H₂O.

Importance of plaster of Paris

(a) It is used in surgical bandages.

(b) It is also used for making casts and moulds.

See, limestone is calcium carbonate which is (CaCO3) okay. 

It's importance is that it is used mainly for preparation of calcium oxide that's (CaO) . This calcium oxide is also called quick lime. 

Next, we come to cement . 

Cement is made up of a lot of compounds. But here, mainly we can say that it is 90% formed from calcium silicates and calcium aluminates .  

The raw materials needed for it's formation are limestone (CaCO3) 

Clay 

Gypsum- which is CaSO4.2H2O  that's calcium sulphate with two water molecules in simple language . 

Now the uses of cement we already know. 

When water is mixed with cement and left for sometime, it becomes very hard . So we use it in building houses bridges and other base infrastructure.  

Last comes POP that's plaster of paris 

It's 2CaSO4.H2O 

It's similar to gypsum, right ? We just saw the formula. 

So simply when gypsum is heated at 120 degree celcuis , we get POP. 

It's a white powder .

Next the importance is, 

Used for setting of broken bones , making toys and blackboard chalks too !

How easy was that ? 

:)