Question

What is the substance used in the manufacturing of cement which produces a large amount of heat when mixed with water?

Answer 1

Hint: Cement is one of the most valuable commodities in modern times.It’s a core component of the construction industry.When mixed with water in appropriate quantities it forms concrete which acts as a binder and keeps the structure safe and secure.

Complete answer:
Let us start by understanding the process of forming cement.
The process of manufacturing Cement is considered to be very complex process.It begins with mining and the subsequent grinding of the essential raw materials which include limestone and clay.The raw materials are grinded to such an extent that a fine powder is formed which is known as raw meal.The raw meal is then heated to a sintering temperature as high as 1450 °C in a cement kiln.During this process, the chemical bonds of the raw materials are broken down and new bonds are formed which then are recombined into new compounds. The result is called clinker, which are rounded nodules between 1 mm and 25mm across. The clinker is ground to a fine powder in a cement mill and mixed with gypsum to create cement. The powdered cement is then mixed with water and aggregates to form concrete that is used in construction.
Out of the various substances used in cement manufacturing,Calcium oxide is a peculiar one.When it reacts with water it forms Calcium hydroxide and gives out a large amount of heat.It’s an exothermic reaction.
 $ CaO + {H_2}O \to Ca{(OH)_2} + Heat $

Note:
Cement is characterised as a typically grey coloured powder.It gets hardened when mixed with water.It’s used as an binder in the construction industry.By changing the quantity of proportion of the raw materials we can manufacture over 20 different varieties of cement.However the strongest of all is Portland cement.