Question

while preparing dilute sulphuric acid from concentrated sulphuric acid in the laboratory, the concentrated sulphuric acid is added slowly to water with constant stirring

Answer 1

because concentrated acid added water it is break down into ion+heat

Answer 2

Explanation:

The addition of concentrated sulphuric acid in water is an exothermic reaction, that is, heat is liberated during this addition.

The amount of heat released during the reaction is very large and if the acid is not added carefully or slowly then it can spur over the skin. As a result, the skin will burn.

To minimize the amount of heat released it is required to constantly stir the solution because this will lead to cooling of the solution. Thus, the acid will not spur.