IIT JEE , AIEEE Forum - Chemistry , Inorganic Chemistry - p

bhuvana89

grp 14 ( c , Si , Ge , Sn , Pb )

1) b.p order : CH4 < SiH4 < GeH4 < SnH4 . why ?

ans - greater the surface area, greater is the vander waal's forces of attraction and higher is the boiling point

2) though CCl4 is not hydrolysed by water , yet it forms COCl2 with superheated steam . why ?

ans - CCl4 is not hydrolysed by water due to non-availability of d orbitals in valence shell of C . but vacant orbitals of higher energy are available with each atom and can be utilised if high energy is provided . so CCl4 reacts with superheated steam to form phosgene.

3) PbCl4 exists . PbBr4 and PbI4 does not . why ?

ans - Cl is a strong oxidising agent and can easily oxidise Pb from +2 oxidation state to +4 . but Br and I are weaker oxidising agents and can't do so.

4) silanes are more reactive than hydrocarbons . why ?

ans - 1) large size of Si than C facilitates attack by nucleophiles
2) greater polarity of Si - X bond ( X = H,C,N,O,F,Cl,I,Br )
3) availability of vacant d orbitals in Si

5) why tin (II) chloride is solid but tin (IV) chloride a liquid ?

ans- tin (II) chloride is an ionic compound and there exists strong force of attraction between tin and chloride ions and so it is solid .
tin (IV) chloride is covalent in which weak intermolecular forces exists & makes it a liquid.

6) why a piece of tin foil is added to SnCl2 solution for preserving it. ??

ans - SnCl2 hydrolyses in solution to liberate HCl .
SnCl2 + H2O ----> Sn(OH)Cl + HCl
in presence of tin foil , HCl reacts to form SnCl2 again and thus helps in

reversing the reaction.

Ask & Discuss Questions with Community & Experts