Given the Lewis structures, indicate the direction of the dipole moment, if there is one.
(a)

Verified step by step guidance

1. Examine the Lewis structure of the molecule to identify the atoms involved and their electronegativities. Recall that electronegativity is the tendency of an atom to attract electrons in a bond. The periodic trend is that electronegativity increases across a period (left to right) and decreases down a group (top to bottom).
2. Determine if the bonds in the molecule are polar. A bond is polar if there is a significant difference in electronegativity between the two atoms. Use the electronegativity values to assess whether the electrons are more attracted to one atom than the other.
3. For each polar bond, indicate the direction of the bond dipole moment. The dipole moment points from the less electronegative atom (partial positive, δ⁺) to the more electronegative atom (partial negative, δ⁻). Represent this with an arrow pointing toward the more electronegative atom, with a small plus sign at the tail of the arrow.
4. Analyze the geometry of the molecule to determine if the individual bond dipoles cancel out or if they combine to create a net dipole moment. Use VSEPR theory to predict the molecular shape and assess the symmetry of the dipoles.
5. If the molecule has a net dipole moment, indicate its direction. The net dipole moment is the vector sum of all individual bond dipoles. If the dipoles cancel out due to symmetry, the molecule is nonpolar; otherwise, it is polar with a net dipole moment in the direction of the resultant vector.

Key Concepts

Lewis Structures

Lewis structures are diagrams that represent the bonding between atoms in a molecule and the lone pairs of electrons that may exist. They help visualize the arrangement of electrons and the connectivity of atoms, which is crucial for understanding molecular geometry and polarity.

Dipole Moment

A dipole moment is a measure of the separation of positive and negative charges in a molecule, indicating its polarity. It is represented as a vector pointing from the positive to the negative charge, and its magnitude depends on the charge difference and the distance between the charges.

Molecular Polarity

Molecular polarity arises from the uneven distribution of electron density within a molecule, often due to differences in electronegativity between bonded atoms. A molecule is polar if it has a net dipole moment, which can affect its physical properties and interactions with other molecules.