Question

what is dilution while diluting an acid why is recomnded thatthe acid should be added to water but not water to the acid

Answer 1

Because adding acid to water is safer than adding water to acid, as it reduces chances of little explosions, which can be dangerous.

Answer 2

Dilution means making the concentration of the solute less by adding more water to it.
It is recommended that the acid should be added to water, so that as the acids sinks down, it gets dissolved. When we add water to acid, the concentration of acid remains too high. Since, it is exothermic, the temperature of the mixture can go too high and the container would become too hot to handle.