A gaseous element 'X' is used in the manufacture of bleaching powder. On reaction with hydrogen, 'X' forms a substance 'Y' which after dissolution in water is used to clean metal surfaces. Identify X and Y. Justify.

Explanation

The element cholrine is used in the manufacture of bleaching power. It reacts with hydrogen to form hydrogen chloride which dissolves in water to gives hydrochloric acid . It is is used to clean the metal surfaces. So 'X' is chlorine and 'Y' is hydrochloride which on dissolution in water gives hydrochloric acid. Metal surfaces have coating of metal oxides and hydrochloric acid can react with the metal oxides and removes the coating.