Question

White wash on wall is exothermic or endothermic reaction and why

Answer 1

white wash means ca(OH)2. which forms by the reaction caco3 +H20 in which "Exothermic Reaction" takes place . Because when caco3 reacts with H2O it produces heat in water and emits co2 gas also and turns water into "milky".

[NOTE:- Caco3 khuch aur nahi hota vo chunna hota hai jo paani ke saath reaction karta aur paani garam hokar kholne lagta hai.]