Question

Question 9.8 What do you understand by

(i) electron-deficient,

(ii) electron-precise, and

(iii) electron-rich compounds of hydrogen? Provide justification with suitable examples.

Class XI Hydrogen Page 289

Answer 1

(i) electron deficient :- Do not have sufficient number of electrons to form normal covalent bonds . in simple you can say that , this type of compounds contain central atom with incomplete octet. example : BH3, AlH3 .these are formed by 13 group. They generally exists in polymeric forms such as B2H6, B4H10 , (AlH3)n etc .

(ii) electron precise hydride :- these type of hydrides have exact number of electrons required to form normal covalent bonds.these are formed by 14 group.these are tetrahedral in shape.
eg., CH4 , SiH4 etc.

(iii) electron rich hydride :- these type of hydrides contains excess number of electron in central atom.e.g., lone pair than required.these are formed by 15,16,17 group elements.e.g., NH3 , H2O , HF etc.these are Lewis bases.

Answer 2

Explanation:

Electron-deficient hydrides: the molecular hydride in which the available valence electrons of the central atom has less than required for Bond formation are called electron deficient hydrides example B2H6 electron precise hydrides demand colour hydrides with all of the valency electrons of central atom are involved in the bond formation ok electron city is hydride examples ch4 electron rich hydrides has raised in which the available valence electrons of the central atom are more than required per word for western ok electron rich hydrides example NH3