Alkane

-ane = 1

-ene = 2

-yne = 3

Alphabetically increasing order. Fuck yea.

Alkyl Halide

X is fluorine, chlorine, iodine, bromine, or astatine.
"If you ever see astatine, your professor is an asshole." - Dr. K 

Alcohol

The reason I have not dropped out yet.

Thiol

Shhhhhhhhh it's orgo lab.

Ether

Ethers go roar like lions. ROR!

Epoxide

Holy shit that looks scary. Example:
[image]

That's better.

Phenol

Alcohols have "-ol" as the suffix [usually].

Aldehyde

Think "COOH" - C double bond O single bond H.

Ketone

Keystones are better than Ketones.

Hemiacetal

Opposite sides.

Amine

Number of Hydrogens determines Primary, Secondary, Tertiary.

Imine

I mean really...Carbon loves double bonding to Nitrogen. 

Carboxylic Acid

C double bond O, single bond OH.

Acid Halide

Halides are any highly electron withdrawing (electronegative) elements - F, Cl, Br... They're really greedy and hate sharing. Just like my friend, Hal.

Remember for MCAT:
Electronegativity increases up and to the right on the periodic table with F being the most electronegative. 

Amide

Amides are "CONs" (C double bond single bond N)

Carbonyl

Little somethin' somethin' to remember for MCAT:

This shit's gonna have a peak at ≈ 1600cm^-1.
The carbonyl stretching absorption is one of the strongest IR absorptions, and is very useful in structure determination as one can determine both the number of carbonyl groups (assuming peaks do not overlap) but also an estimation of which types.