JAMB - Chemistry (2003 - No. 30)
Chlorine gas is prepared in the laboratory by
adding concentrated hydrochloric acid to solid manganese (IV) oxide
aciding concentrated tetraoxosulphate (VI) acid to solid sodium chloride
dropping concentrated hydrochloric acid onto potassium tetraoxomanganate (VI) crystals
aciding concentrated tetraoxosulphate (VI) acid to hydrochloric acid
Explication
Chlorine gas is prepared in the laboratory by adding an oxidizing agent e.g. \(MnO_2\), \(PbO_2\), or \(KMnO_4\) on concentrated hydrochloric acid.
\(MnO_{2(s)}\) + 4\(HCl_{aq}\) → \(MnO_{2(aq)}\) + 2\(H_2O_{(l)}\) + \(Cl_{2(g)}\)