Line 'Em Up
VESPR Visions
Complex Centers
Funky Functions
Bonding Patterns
100
In a line drawing, what atom is assumed to be located at every "bend" and "end"?
Carbon
100
According to VSEPR theory, why do regions of high electron density locate as far apart as possible from one another?
To minimize electron repulsions
100
True or False: Complex molecules like Ethanol (CH3CH2OH) only have one central atom.
False
100
What functional group consists of an oxygen atom single-bonded directly to a hydrogen atom (R-O-H)?
Alcohol
100
To achieve a neutral charge, how many bonds does a standard Carbon atom expect to form?
4
200
What atom is omitted from line structures?
Hydrogens bonded directly to carbon atoms
200
What is the ideal bond angle for a central atom that has a linear Electron Domain Geometry?
180
200
In the molecule Acetone (CH3COCH3), what is the expected approximate bond angle around the outer CH3 carbon atoms?
~109/109.5
200
Identify the functional group characterized by a nitrogen atom single-bonded to one or more carbon groups.
Amine
200
How many bonds and lone pairs does a standard, neutral Nitrogen atom expect to have?
3 bonds and 1 lone pair
300
True or False: Lone pairs of electrons must always be drawn on a valid line structure.
False
300
If a central atom has 3 electron domains and all 3 are bonding pairs, what is its expected molecular geometry?
Trigonal Planar
300
The central carbon in Acetone is double-bonded to an oxygen and single-bonded to two other carbons. What is its Electron Domain Geometry?
Trigonal Planar
300
What is the primary structural difference between a Ketone and an Aldehyde?
A ketone features a carbonyl carbon bonded to two other carbons, while an aldehyde's carbonyl carbon is bonded to at least one hydrogen.
300
If an atom has one more bond than its expected neutral bonding capacity, what happens to its charge?
It takes on a +1 formal charge
400
If a carbon atom in a line structure is shown having only one double bond and no other drawn lines or atoms, how many implicit hydrogens are attached to it?
2 hydrogens
400
A molecule's central atom has 4 total electron domains, but one of those is a lone pair. What is its Electron Domain Geometry (EDG) and its Molecular Geometry (MG)?
EDG = Tetrahedral
MG = Trigonal Pyramidal
400
Why do we use the "approximately" symbol (~) when describing bond angles in complex molecules, rather than exact ideal degrees?
Because the differing sizes of surrounding substituent groups and the presence of lone pairs slightly alter the exact repulsion forces.
400
Identify the functional group that features a central carbon double-bonded to an oxygen and single-bonded to a nitrogen atom.
Amide
400
A standard, neutral Oxygen atom expects 2 bonds. If it instead has 1 single bond and 3 lone pairs, what is its expected charge?
-1
500
Describe or draw the correct line structure for Formamide (NH2CHO).
Central carbon double-bonded to an Oxygen, single-bonded to an NH2, Hydrogen bonded to the carbon is omitted.
500
Explain the fundamental difference between Electron Domain Geometry (EDG) and Molecular Geometry (MG).
EDG considers the arrangement of all electron domains (bonds and lone pairs), while MG only describes the arrangement of the bonded atoms.
500
Analyze the oxygen atom in Ethanol (CH3CH2OH). State its number of electron domains, its EDG, and its approximate bond angle.
4 domains (2 bonds, 2 lone pairs)
Tetrahedral EDG
~109
500
Look at the projected structure of Phenylalanine. Name three functional groups present in this biochemical molecule.
Phenyl (aromatic ring), Amine, and Carboxylic Acid.
500
Predict the charge on a Carbon atom that possesses only 3 bonds and zero lone pairs.
+1