WAEC Chemistry 2019 Theory — Question 22

Model answer

(i) Dry chlorine gas is prepared in the laboratory by heating concentrated hydrochloric acid with manganese(IV) oxide (MnO2) in a flask; the gas produced is passed through concentrated H2SO4 (to dry it) and collected by downward delivery (chlorine is denser than air), as shown in the labelled diagram. (ii) Chlorine is used for water purification/disinfection, and for the manufacture of important organic solvents such as tetrachloromethane and trichloromethane (it is also used in bleaching powder manufacture and aerosol propellants).