What is the reaction of sulphuric acid in water?

Answer 1

It is an exo thermal reaction. It means, heat is produced when they get mixed together.

So, we have to be very, very careful while adding water with sulphuric acid, in case to get it diluted, because enormous heat will be produced.

You should not pour water on sulphuric acid kept in a bowl. It is very dangerous. Why?

Just think. When you pour water on sulphuric acid, enormous heat will be produced which make water to expand abruptly and so an explosion becomes possible which in turn spills the acid all around and even on the person who has poured water on it.

So the intelligent way is, instead adding water to the acid it will be better adding acid to water. That too, using a glass rod. Sulphuric acid is poured in smaller amount at top edge of the glass rod kept inclined in a bowl containing water. The acid slowly descends into the water and as soon as it descends heat will be produced. So using another glass rod we have to stir well the water in the bowl so that the heat produced will be distributed all over.

This is the right technique to prepare dilute sulphuric acid.

The balanced equation is:

H2SO4 + 2H2O -> 2H3O+ + SO42-