Polarity and Isomers Flashcards
What is molecular polarity?
The distribution of charge in a molecule
What is bond polarity?
The electronegativity difference between bonded atoms, creating partially charged poles
What qualities influence molecular polarity?
Bond polarity and shape
What is a dipole moment (μ)?
A measure of bond polarity
What are the units for a dipole moment?
Debye (D)
What two things need to be true for a molecule to be polar?
- The molecule has 1 or more polar bonds
- The individual bond dipoles don’t cancel out
Are symmetrical molecules usually polar or nonpolar?
Usually nonpolar
How can a molecule with polar bonds be nonpolar?
If the individual bond polarities cancel out
Example: CO2
What can cause molecules with the same shape to have different polarities?
Having different atoms causes different polarities
In a polar bond, the polarity points towards which atom?
The more electronegative one
When a molecule has polar bonds but all neighboring atoms are the same and arranged symmetrically around the central atom, is it usually polar or nonpolar?
Nonpolar because the dipoles cancel
When a molecule has polar bonds and at least one lone pair, is it usually polar or nonpolar?
Polar
Exceptions: square planar (AX4E2) and linear (AX2E3) molecules
What are isomers?
Molecules with the same chemical formula but
different arrangement of atoms
What are stereoisomers?
Molecules with the same connections of atoms but different spatial arrangements
If a stereoisomer has the same atoms on one side, is it cis or trans?
Cis
