Intro to Organic Chem Flashcards
What does bond order describe?
whether a covalent bond is single, double or triple
What is the bond order of a single, double, and triple bond?
single –> bond order = 1
double –> bond order = 2
triple –> bond order = 3
How many sigma bonds and/or pi bonds are found in a single bond?
1 sigma bond
How many sigma bonds and/or pi bonds are founc in a double bond?
one sigma and one pi
How many sigma bonds and/or pi bonds are found in a triple bond?
one sigma bond and 2 pi bonds
TRUE or FALSE: potential energy is directly proportional to bond strength.
FALSE –> potential energy is inversely proportional to bond strength
TRUE or FALSE: bond length is inversely proportional to bond strenght.
TRUE
What is the formula for formal charge?
formal charge = (# of valence electrons in free atom) - (# of electrons in lone pair) - (# of bonds)
TRUE or FALSE: In a Lewis diagram, the central atom is usually the least electronegative.
TRUE
What are 4 things to look out for when determining the MAJOR resonance structure?
- full octet
- minimum number of formal charges
- negative FC on electronegative atoms
- minimum separation between opposite FCs
What does VSEPR stand for?
valence shell electron pair repulsion
TRUE or FALSE: lone pairs contribute to the determination of the geometry of a molecule, using VSEPR theory.
TRUE
Provide the number of groups, bond angle(s), central atom hybridization for the following basic geometry:
Linear
(note: number of groups = number of atoms and lone pairs connected to the central atom)
number of groups = 2
bond angle = 180
hybridization = sp
Provide the number of groups, bond angle(s), central atom hybridization for the following basic geometry:
Trigonal planar
(note: number of groups = number of atoms and lone pairs connected to the central atom)
number of groups = 3
bond angle = 120
hybridization = sp2
Provide the number of groups, bond angle(s), central atom hybridization for the following basic geometry:
Tetrahedral
(note: number of groups = number of atoms and lone pairs connected to the central atom)
number of groups = 4
bond angle = 109.5
hybridization = sp3
Provide the number of groups, bond angle(s), central atom hybridization for the following basic geometry:
trigonal bipyramidal
(note: number of groups = number of atoms and lone pairs connected to the central atom)
number of groups = 5
bond angle = 90, 120
hybridization = sp3d
Provide the number of groups, bond angle(s), central atom hybridization for the following basic geometry:
octahedral
(note: number of groups = number of atoms and lone pairs connected to the central atom)
number of groups = 6
bond angle = 90
hybridization = sp3d2
TRUE or FALSE: each bond in a double bond contributes individually to the hybridization of an atom.
FALSE –> double bonds do NOT contribute individually to hybridization
If an atom has a choice between sp2 and sp3, it chooses _______.
sp2
What is the geometrical name for a molecule that has 2 groups and alone pair?
bent
What is the geometrical name for a molecule with 2 lone pairs and 2 groups?
bent
TRUE or FALSE: electron delocalization decreases a molecule’s stability.
FALSE: electron delocalization INCREASES a molecule’s stability
What is the name of the rule used to determine if a compound is aromatic? Provide the guidelines.
Huckel’s Rule…a molecule is aromatic if it is:
- planar
- cyclic
- fully conjugated (alternating single and double bonds)
- contains a total of 4n+2 pi electrons (where n = 0, 1, 2, 3, etc.)
note: all carbons must be sp2 hybridized