Question

why should we always pour the acid into water and not water into acid...

Answer 1

First, adding more acid releases more heat, as it is exothermic. If you add water to acid it forms an extremely concentrated solution of acid initially. So much heat is released that the solution may boil very violently, splashing concentrated acid out of the container and all this because the reaction is exothermic

Answer 2

We always pour acid into water 'cause If you add water to acid it forms an extremely concentrated solution of acid initially. So much heat is released that the solution may boil very violently, splashing concentrated acid out of the container and all this because the reaction is exothermic.
Hope this will help!!