What do you understand by 

(i) electron rich – compounds of hydrogen, 

(ii) electron-precise, and 

(iii) electron-deficient? Provide justification with suitable examples.

Asked by Abhisek | 1 year ago |  134

1 Answer

Solution :-

Molecular hydride is classified on the basis of the presence of the bonds and total number of electrons in their Lewis structures as:

  1. Electron-deficient hydrides
  2. Electron-precise hydrides
  3. Electron-rich hydrides

An electron-deficient hydride has very less electrons, less than that required for representing its conventional Lewis structure.

 E.g

Diborane (B2 H6)

In B2 H6, there are 6 bonds in all, out of which only 4 bonds are regular 2 centered-2 electron bonds.

The remaining 2 bonds are 3 centered-2 electron bonds i.e., 2 electrons are shared by 3 atoms. Hence, its conventional Lewis structure cannot be drawn.

By conventional Lewis structure, an electron-precise hydride has a sufficient number of electrons to be represented.

 e.g. CH4

The Lewis structure can be written as:

4 regular bonds are formed where 2 electrons are shared by 2 atoms. An electron-rich hydride contains excess electrons as lone pairs.

 e.g. NH3

There are 3 regular bonds in all with a lone pair of electrons on the nitrogen atom.

Answered by Pragya Singh | 1 year ago

Related Questions

What do you understand by the terms :

(i) Hydrogen economy 

(ii) Hydrogenation 

(iii) ‘syngas’ 

(iv) Water-gas shift reaction 

(v) Fuel cell?

Class 11 Chemistry Hydrogen View Answer

Do you expect different products in solution when aluminium (III) chloride and potassium chloride treated separately with 

(i) alkaline water 

(ii) acidified water, and 

(iii) normal water. Write equations wherever necessary.

Class 11 Chemistry Hydrogen View Answer

What do you expect the nature of hydrides is, if formed by elements of atomic numbers 15, 19, 23 and 44 with dihydrogen? Compare their behaviour with water.

Class 11 Chemistry Hydrogen View Answer

How can saline hydrides remove traces of water from organic compounds?

Class 11 Chemistry Hydrogen View Answer