A. Is CCl4 polar or nonpolar? F B. Is NOBr polar or nonpolar? C. Is NICI2 polar or nonpolar?
The Correct Answer and Explanation is:
Here are the correct answers and explanations for the polarity of the given molecules:
A. Is CCl₄ polar or nonpolar?
Answer: Nonpolar
Explanation:
Carbon tetrachloride (CCl₄) consists of a central carbon atom bonded to four chlorine atoms. Each C–Cl bond is polar because chlorine is more electronegative than carbon, creating a dipole moment pointing toward the chlorine atoms. However, the molecule has a tetrahedral geometry, which is symmetrical. This symmetry causes the individual dipole moments to cancel out because they are equal in magnitude and point in opposite directions. As a result, despite having polar bonds, the overall molecule is nonpolar due to the net dipole moment being zero.
B. Is NOBr polar or nonpolar?
Answer: Polar
Explanation:
Nitrosyl bromide (NOBr) has a linear or bent molecular geometry depending on how you interpret its electron arrangement, but the key point is that the atoms (nitrogen, oxygen, and bromine) have significantly different electronegativities. Oxygen is the most electronegative, followed by nitrogen, then bromine. This creates an uneven distribution of electron density across the molecule. The N=O bond is much more polar than the N–Br bond, resulting in a net dipole moment pointing from bromine toward oxygen. Because the dipoles do not cancel, NOBr is a polar molecule.
C. Is NICl₂ polar or nonpolar?
Answer: Polar
Explanation:
Niodium dichloride (NICl₂) consists of a nitrogen (N) atom bonded to one iodine (I) and two chlorine (Cl) atoms. The molecule has a trigonal planar or bent geometry (depending on the bonding and lone pairs on nitrogen), but the critical aspect is that chlorine and iodine have different electronegativities. Chlorine is more electronegative than iodine, creating unequal dipole moments in the N–Cl and N–I bonds. The asymmetry of the molecular shape and the difference in electronegativity among the atoms causes the dipole moments not to cancel out. Therefore, NICl₂ is a polar molecule.
Summary:
- CCl₄ – Nonpolar (symmetrical tetrahedral, dipoles cancel)
- NOBr – Polar (uneven electronegativity, dipoles don’t cancel)
- NICl₂ – Polar (asymmetrical, mixed electronegativities, net dipole)
