Question

Write the Lewis structure for each molecule (octet rule not followed). A. BBr3 b. NO c. ClO2

Answer 1

Answer : The Lewis-dot structure for the given molecule are shown below.

Explanation :

Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule.

In the Lewis-dot structure the valance electrons are shown by 'dot'.

(a) The given molecule is,
`BBr_3`

As we know that boron has '3' valence electrons and bromine has '7' valence electron.

Therefore, the total number of valence electrons in
`BBr_3` = 3 + 3(7) = 24

According to Lewis-dot structure, there are 6 number of bonding electrons and 18 number of non-bonding electrons.

(b) The given molecule is,
`NO`

As we know that nitrogen has '5' valence electrons and oxygen has '6' valence electron.

Therefore, the total number of valence electrons in
`NO` = 5 + 6 = 11

According to Lewis-dot structure, there are 4 number of bonding electrons and 7 number of non-bonding electrons.

(c) The given molecule is,
`ClO_2`

As we know that chlorine has '7' valence electrons and oxygen has '6' valence electron.

Therefore, the total number of valence electrons in
`ClO_2` = 7 + 2(6) = 19

According to Lewis-dot structure, there are 4 number of bonding electrons and 15 number of non-bonding electrons.

Answer 2

A.⇒ The BBr3 have Br are in Group 7 and have 7 valence electrons.

Boron (Boron often only needs 6). B in BBr3 only has 6 valence electrons.

For the BBr3 Lewis structure there are a total of 24 valence electrons.

b.⇒The valence electrons you have available are: 1 N + 1 O = 1×5 + 1×6 = 11

The trial structure has three extra electrons. We have to insert one or more double bonds. With three electrons, we can make only one double bond with one electron left over: N=O. an odd number of electrons (11), we cannot give every atom an octet.

c.⇒Connect the atoms with single bonds. Chlorine is the central atom. Connect the atoms with single bonds

Where n in this case is 3 since ClO2 consists of three atoms.

Where V = (6 + 6 + 7 ) = 19

Since the number of valence electrons is odd the octet rule will not be obeyed in all atoms.