few molecules/ ions are given in Table . . Table . The Lewis Representation of Some Molecules * Each H atom attains the configuration of helium (a duplet of electrons) C H molecule Problem .
Write the Lewis dot structure of CO molecule. Solution Step . Count the total number of valence electrons of carbon and oxygen atoms. The outer (valence) shell configurations of carbon and oxygen atoms are: s p and s p , respectively.
The valence electrons available are + = . Step . The skeletal structure of CO is written as: C O Step . Draw a single bond (one shared electron pair) between C and O and complete the octet on O, the remaining two electrons are the lone pair on C.
This does not complete the octet on carbon and hence we have to resort to multiple bonding (in this case a triple bond) between C and O atoms. This satisfies the octet rule condition for both atoms. Problem . Write the Lewis structure of the nitrite ion, NO – .
Solution Step . Count the total number of valence electrons of the nitrogen atom, the oxygen atoms and the additional one negative charge (equal to one electron). N( s p ), O ( s p ) + ( × ) + = electrons Step . The skeletal structure of NO – is written as : O N O Step .
Draw a single bond (one shared electron pair) between the nitrogen and each of the oxygen atoms completing the octets on oxygen atoms. This, however, does not complete the octet on nitrogen if the remaining two electrons constitute lone pair on it. Hence we have to resort to multiple bonding between nitrogen and one of the oxygen atoms (in this case a double bond). This leads to the following Lewis dot structures.
. . Formal Charge Lewis dot structures, in general, do not represent the actual shapes of the molecules. In case of polyatomic