Give reasons of the following :
(i) LiI is covalent
(ii) SiF4 is non polar
(iii) Which is more acidic anhydrous HCl or aqueous HCl and why ?
(iv) PCl5 is covalently bonded liquid but when added to water , the solution conducts electricity why ?
(v) PCl5 exist in solid state in the form of { PCl4]+[PCl6]-- yet it is non conducting .
Answers
Answer:
1.Size of lithium ion is very small whereas size of iodine ion is very large. Thus, according to Fajan's rule smaller is the size of cation more will be its polarizing power and larger is the size of anion more will be its polarizability. Hence, this results in the formation of covalent bond.
2.SiF4 is a nonpolar molecule because the fluorine atoms are arranged around the central silicon atom in a tetrahedral molecule with all of the regions of negative charge cancelling each other out.
3.In the presence of water which is dipolar in nature, there is a dipolar interaction between the H+andCl- ions of the acid and the surroundisng H2O molecules. ... Therefore, aqueous HCl is a stronger acid as compared to anhydrous HCl.
4.When PCl5 dissolves in water or gets converted in its solution, it converts into PCl6- and PCl4+ ions. As now it has ions [ or free e- ] it can now conduct electricity as free electrons allows any molecule to conduct electricity.
5.PCl5 exists as solid in the form of [PCl4]+ [PCl6]- , and it is a non conductor of electricity.