63Eb - Organic Chemistry (Mcmurry)

Question

Determine if each compound or ion below has a dipole moment.

(a) Carbonate ion  $\left({{\mathbf{CO}}_3}^{2-}\right)$

(b)  $\mathbf{-}\underset{\mathrm{..}}{\overset{\mathrm{..}}{O}}\mathbf{-}$

(c) $\stackrel{+}{C}{\left({\mathbf{CH}}_3\right)}_3$

Step-by-Step Solution

Answer

Dimethyl ether ${\text{(CH}}_{\text{3}}{\text{-O-CH}}_{\text{3}}\text{)}$  has a dipole moment.

Structure of Dimethyl ether

IUPAC name of dimethyl ether is methoxymethane, and its chemical formula is $\left({\text{CH}}_{\text{3}}{\text{-O-CH}}_{\text{3}}\right)$ . The oxygen atom has two lone pairs on it.

Identify whether dimethyl ether has a dipole moment or not

To identify the dipole moment of dimethyl ether, we will identify the shape of the molecule by steric number. The formula for finding steric number (S) is

 S = number of lone pairs + number of bond pairs

Therefore, the steric number for an oxygen atom in dimethyl ether is 4. So its hybridization is $S{p}^3$  , and the shape of the compound is tetrahedral. Due to the presence of lone pairs on the oxygen atom, it has a dipole moment, and its direction will be in the upward direction.