When salt is formed?
Salt formation takes place by the neutralisation reaction , the details of which can be found out in the link below:-
https://www.meritnation.com/ask-answer/question/what-is-neutralisation-reaction-give-two-examples/chemical-reactions-and-equations/4842137
https://www.meritnation.com/ask-answer/question/what-is-neutralisation-reaction-give-two-examples/chemical-reactions-and-equations/4842137