Question

Assertion: while dissolving an acid or base in water, the acids must always be added slowly to water with constant stirring Reason: dissolving an acid on a base in water in highly exothermic reaction

Answer 1

Answer:

both are correct and (R) is correct explanation of (A)

Answer 2

Answer:

While dissolving acid or base in water it is highly exothermic and when acid or base is dissolved in water constant stirring should also be done so that acid or base slowly dissolved in water and could not create high temperature. In some case when acid would dissolved in water so that beaker or any test tube or whatever u take on surrounding ice should also be kept , so that beaker can not become very hot. if we dissolve water to acid there would be splash n that burn our face and other body parts. so it is said that we have to always dissolve acid or base to water.  

hope this help u