Question

Indicate whether each of the following molecules is polar or nonpolar. You may wish to review the chapter on chemical bonding and molecular geometry.

a. H₂O - Polar
b. CO₂ - Nonpolar
c. NH₃ - Polar
d. CH₄ - Nonpolar

Answer 1

H₂O is polar due to its bent shape and electronegativity differences between oxygen and hydrogen. CO₂ is nonpolar because its linear shape allows its polarities to cancel out. NH₃ is polar due to its trigonal pyramidal shape and electronegativity differences, while CH₄ is nonpolar thanks to its symmetric tetrahedral geometry.

Step-by-step explanation:

The polarity of a molecule can be determined by its molecular geometry and the electronegativity of its atoms. Here are the polarities of the given molecules:

• H₂O (Water) is polar. It has a bent shape with oxygen having a higher electronegativity than hydrogen, and it features lone pairs of electrons on the central atom, leading to an uneven distribution of charge.
• CO₂ (Carbon Dioxide) is nonpolar. Despite containing polar bonds, the molecule is linear, which causes the polarities to cancel each other out, resulting in no net dipole moment.
• NH₃ (Ammonia) is polar. Its trigonal pyramidal shape and the difference in electronegativities between nitrogen and hydrogen lead to a net dipole moment.
• CH₄ (Methane) is nonpolar. Methane has a tetrahedral geometry and is symmetric, thus the bond dipoles cancel out.