How to purify air with activated charcoal ("Adsorption" experiment)

For cool and safe chemistry experiments to do at home sign up to MEL Science here: This spec­tac­u­lar ex­per­i­ment shows how air is pu­ri­fied in gas masks and oth­er pu­ri­fy­ing de­vices, us­ing ac­tive char­coal. Reagents and equip­ment: * cop­per; * con­cen­trat­ed ni­tric acid; * ac­tive char­coal; * con­ic flasks (3); * stop­pers (2); * stop­per with a gas pipe (1). Step-by-step in­struc­tions Pre­pare three flasks, two with stop­pers and one with a gas pipe. Place cop­per in the flask with a gas pipe and pour in con­cen­trat­ed ni­tric acid. A brown gas starts to be re­leased vi­o­lent­ly – ni­tro­gen diox­ide, which we pour into the two flasks and seal them with stop­pers. Af­ter a while, when we are sure that our sys­tems are her­met­ic, we add tablets of ac­tive char­coal to one of the flasks. Pro­cess­es de­scrip­tion Sev­er­al min­utes lat­er, in the flask with the ac­tive char­coal, the gas will grad­u­al­ly s