Molecular Geometry Flashcards
(29 cards)
Bond Angles
Based on electron domain geometries (number of domains).
What is bond angle of linear?
180 Degrees
What is bond angle of trigonal planar?
120 Degrees
What is bond angle of tetrahedral?
109.5 Degrees
What is the bond angle of trigonal bipyramidal
The whole thing is 180 degrees, however up and down is 90 degrees, side to side is 120 degrees.
What is the bond angle of octahedral?
90 Degrees
2 types of trigonal bipyramidal, what are they?
Equatorial and Axial positions.
What is an equatorial position?
Three bonds arranged in a trigonal plane.
What is an axial position?
Perpendicular to the trigonal plane.
What is molecular geometry?
The shape the atoms themselves make.
Do lone pairs affect the shape?
Yes, but not used in the descriptive name of the shape.
How to determine molecular geometry?
Number of domains + number of lone pairs on the central atom.
Electronic Geometry
Arrangement of electron pairs around a central atom.
Molecular Geometry
Arrangement of atoms instead of electrons.
Bond Angles
The angle between the two bonds, based on electron domain geometries.
Multiple bonds occupy how much space?
A lot of pace, more space than single bonds.
How do bonds and electrons affect shape?
The bonds and electron density causes higher repulsions, causing other bond angles to compress.
Multi-Center Molecules
Molecules that does not contain a single central atom.
What makes a bond polar covalent?
If the difference in electronegativity between the two atoms in the bond is between 0.4 - 1.8
Bond Dipole
Partial charges on the atoms in covalent bond due to electronegativity.
How to calculate dipole moment (µ)?
µ = Q x r
What does Q stand for in dipole moment?
Q is the magnitude of the partial charge and r is the distance between the charges.
How to calculate overall dipole moment for the molecule?
The vectors for each bond in a molecule can be added to find the overall dipole moment for the molecule.
What are the factors that affect polarity of of a molecule/compound?
Direction of bonds, and magnitudes of electronegativity. Remember vectors have direction and magnitude.
