Question
Give reasons for the following:
(a) PCl5 acts as a chlorinating agent in organic reactions.
(b) Nitric oxide becomes brown when released in air.
(c) PCl5 is ionic in nature in the solid state.
(d) Ammonia acts as a ligand.
(e) Sulphur disappears when boiled with an aqueous solution of sodium sulphite.
Solution
(a) PCl5 has a trigonal bipyramidal shape in which P—Cl (axial) bonds are slightly larger than the P—Cl (equatorial) bonds. This makes the molecule, rather, unstable. It dissociates to lose two chlorine atoms involved in the axial bonds and thus, acts as a chlorinating agent.
(b) It is because N6 reacts with O2 to form nitrogen dioxide which is brown in colour
(b) It is because N6 reacts with O2 to form nitrogen dioxide which is brown in colour
(c) PCl5 is ionic in nature in solid state because it exists as [PCl4]+ [PCl5]–
(d) NH3 has lone pair of electron, therefore, acts as ligand.
(e) It is due to formation of sodium thiosulphate.
