Question

Statement 1: In the complex $[Co(NH_{3})_{3}Cl_{3}],$ chloride ions satisfy the primary valencies as well as the secondary valencies o f cobalt metal.
Statement 2:$[CO(NH_{3})_{3}Cl_{3}]$ shows geometrical as well as optical isomerism.

• A. If both Statement 1 and Statement 2 are true and the statement 2 is the correct explanation o f the statement 1.
• B. Ifboth Statement 1 and Statement 2 are true but statement 2 is not the correct explanation of the statement 1.
• C. If Statement 1 is true but Statement 2 is false.
• D. If Statement 1 is false but Statement 2 is true.

Answer 1

Answer: (C)

Statement 1: Every element tends to satisfy both its primary and secondary valencies. In order to meet this requirement a negative ion may often show a dual behaviour, i.e. it may satisfy both primary and secondary valencies since in every case the fulfillment of coordination number of the central metal ion appears essential. This dual behaviour is represented by both thick and dotted lines.

Statement 2: Complex $[CO(NH_{3})_{3}Cl_{3}]$ may show two isomeric forms called fac- and mer-. Facial isomers have three identical ligands on one triangular face whereas meridional isomers have three identical ligands in a plane bisecting the molecule. It does not show optical isomerism because of the presence of plane of symmetry.