Unit 1: Structure & Bonding Study Set

hydrocarbons

molecules that contain only hydrogen and carbon

straight-chain alkanes

compouds whose carbons are all connected in a row

branches-chain alkanes

compounds whose carbons branch

isomers

compounds that have the same formula but different structures

constitutional isomers

compounds whose atoms are connected differently; ccompounds are different with different properties but have the same formula

ex: C₄H₁₀ forms both butane and isobutane

skeletal structures

structures where:

1. carbon atoms aren’t shown, they’re at each line (bond) intersection

2. hydrogen atoms bonded to carbon aren’t shown, they’re implied/implicit whilst hydrogen atoms attached to non-carbon atoms are shown

3. atoms other than carbon and hydrogen are shown

4. lone pairs are optional

formal charge

signs that don’t imply the presence of actual ionic charges but are instead used to keep track of electrons; they are only associated with atoms that don’t exhibit the appropriate number of valence electrons and have to be shown in skeletal structures

formal charge equation

# of valence electrons - # of bonds - 2(# of lone pairs)

resonance structures

structures with the same connectivity but have a different arrangement of lone pairs and pi bonds

curved/resonance arrows

things that show the movement of electrons between atoms

they can:

1. never break a single bond (would change the connectivity)

2. never exceed an octet for a second-row element

3. not change the charges, structure must have the same charge it had before drawing this

tail

shows where the source of electrons comes from on a curved arrow

head

shows where the electrons are going on a curved arrow

resonance hybrid

an unchanging structure that exhibits characteristics from each of its resonance forms