Q. 6.83 - An Introduction to General, Organic, and Biological Chemistry

Question

The molecule ${\mathrm{CO}}_2$ is nonpolar, but $\mathrm{CO}$ is a polar molecule. Explain.

Step-by-Step Solution

Answer

Due to electronegativity difference between carbon and oxygen atom ${\mathrm{CO}}_2$ is nonpolar, but $\mathrm{CO}$ is a polar molecule.

Step 1 : Given information

We are given ${\mathrm{CO}}_2$ is nonpolar, but $\mathrm{CO}$  is a polar molecule

Step 2 : Simplify

Because the electronegativities of carbon and oxygen differ from each other, electrons are not shared equally between the two atoms.
However, because ${\mathrm{CO}}_2$ geometry is linear, the two bond dipole moments cancel out, leaving no net molecule dipole moment.
The molecule is thus non-polar.