Question

Why acid added to water and not water to acid

Answer 1

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.An exothermic reaction is a chemical reaction that releases energy by light or heat. If you add water to a concentrated acid the heat released can cause an explosion, spreading acid throughout a room. Adding the acid or base to the larger volume of water allows the heat to dissipate safely.

Answer 2

ACID IS ADDED TO WATER AS THIS WOULD DILUTE THE ACID.SINCE ON DILUTING AN ACID VOLUME OF SOLUTUION INCREASES BUT VOLUME OF IONS REMAINS SAME.SO,CONCENTRATION OF H PLUS IONS DECREASES PER UNIT VOLUME.
ALSO ON ADDING WATER TO ACID THE HEAT GENERATED MAY CAUSE THE MIXTURE TO SPLASH OUT AND CAUSE BURNS.