(i) Anhydrous AlCl₃ is an electro-deficient compound while hydrated AICl₃ is not.
(ii) Therefore, anhydrous AICl₃ is more soluble in diethyl either because the oxygen atom of ether donates a pair of electrons to the vacant p-orbital on the Al atom in AlCl₃ forming a co-ordinate bond.
(iii) In case of hydrated AlCl₃, Al is not electron deficient, since, H₂O has already donated a pair of e^- to it.

(i) Borax - Na₂[B₄O₅.(OH)₄].8H₂O
(ii) Kernite - Na₂[B₄O₅(OH)₄]·2H₂O

(i) Zeolites have a three dimensional crystalline structure looks like a honeycomb consisting of a network of interconnected tunnels and cages.
(ii) Water molecules moves freely in and out of these pores hence they are highly porous.

(i) In the elements of 4^th, 5^th and 6^th period of the p-block the electrons present in the intervening d and f - orbitals do not shield the s-electrons of the valence shell effectively.
(ii) As a result, ns²-electons remains more tightly held by the nucleus and hence do not participate in bonding. This is called inert pair effect.

(i) Silicon tetrachloride is used in the production of semiconducting silicon.
(ii) It is used as a starting material in the synthesis of silica gel, silicic esters, a binder for ceramic materials.