Question

6. Al, Ga and In form cyanides with composition M(CN), and M coordination 6. The corresponding cyanide of TI (thallium) has a stoichiometry TI(CN)2 with two chemically different kinds of thallium. Explain why and speculate on the structure of the compound [hint: structure similar to Zn(CN)2l 7. The most common chlorides of C, Si, Ge and Sn are covalent and have compositions MCl. The most stable chloride of Pb is ionic with composition PbCl2. Explain the difference in stability (chemical behavior) among the latter and the other group IV chlorides.

Answer 1

All IIIA group elements exhibts +3 oxidation state. But Thallium exhibts +1 , +3 oxidation state.+1 oxidation state is more stable for Thallium due to inert pair effect.

In heavier elements valency shell S-orbital two electrons are not participate in chemical bond thier remains the pair is called inert pair effect.

7.All IVA group elements exhibts +4 oxidation state. But Lead exhibts +2 , +4 oxidation state.+2 oxidation state is more stable for Lead due to inert pair effect.

All IVA group elements form MCl4 trahalides except Pb. Lead form only form PCl2 dichlorides due to inert pair effect.