Question

Which molecules are polar?

a) N₂
b) HBr
c) CH₃Cl
d) CCl₄
e) H₂S
f) BBr₃

Answer 1

The polar molecules from the list provided are HBr and CH3Cl due to the presence of polar bonds and asymmetrical structures. Nonpolar molecules include N2, CCl4, and BBr3 as they either have symmetrical shapes that cancel out dipoles or consist of identical atoms.

Step-by-step explanation:

Among the molecules listed, the polar ones are those with an uneven distribution of electron density or those that contain polar bonds that do not cancel out. These are:

• HBr - Hydrogen bromide is polar due to a difference in electronegativity between hydrogen and bromine, resulting in a polar bond.
• CH₃Cl - Methyl chloride is polar because the carbon-hydrogen bonds are less polar than the carbon-chlorine bond, causing an overall dipole moment.

• N₂ - Nitrogen gas is nonpolar as it consists of two nitrogen atoms sharing electrons equally.
• CCl₄ - Carbon tetrachloride is nonpolar. While it contains polar C-Cl bonds, the molecule's symmetrical tetrahedral shape means the dipoles cancel each other out.
• H₂S - Hydrogen sulfide is polar due to the bent shape of the molecule, which does not allow the dipoles to cancel out completely.
• BBr₃ - Boron tribromide is nonpolar because of its symmetrical trigonal planar shape, causing the dipoles to cancel each other out.