Question

While diluting concentrated sulphuric acid, the acid should be added to water and not water to the acid. Explain why? [3 MARKS]

Answer 1

The sulphuric acid reacts with water producing a large amount of heat energy. While diluting, the concentrated sulphuric acid should be added to water because acid being heavier, it settles down and the evolved heat is dissipated in the water itself, and hence the spurting of acid. The water on coming in contact with acid suddenly changes to steam by the heat produced during the reaction. The acid being in bulk tends to spurt out with serious consequences.