Chem Hour 1

difference between alkane, alkene, alkyne

an —> single bond

en —> double bond

alkyne —> triple bond

—OH functional group

alcohol

• ol suffix ending

—CHO functional group

aldehyde

• al suffix ending

C == O functional group

Ketone

• one suffix ending

—COOH functional group

Carboxylic acid

• oic acid suffix ending

—COOR functional group

Ester

• oate suffix ending

—NH2 functional group

Amine

• amine suffix ending

—CONH2 functional group

Amide

• amide suffix ending

Names and examples of alkyl halides..

Ex. —Cl, —Br, —F, —I

Named as prefixes: chloro-, bromo-, fluoro-, etc.

Describe Alkene/Bond Stability & 3 Factors (ranked from MOST → LEAST)

Key Rule: More Stable = lower energy

1. Substitution (Hyperconjugation)

2. Conjugation

3. Cis vs Trans (Sterics)

Substitution…

• More alkyl groups attached → more stable

• Tetra substituted > Tri > Di . Mono

Conjugation…

Cis vs Trans…

Trans is more stable than Cis

• Less crowding → more stable

Anion Stability & Factors that affect

Key Idea: More stable anion = WEAKER base

1. Electronegativity

2. Resonance

3. Atom s-Character

Electronegativity…

the more electronegative an atom → the more stable

Example O- > N- > C-

Resonance…

Charge spread out → more stable

Atomic Size..

• Larger atoms = more stable

• Ex. I- > Br- > Cl- > F-

S-character (hybridization)

More s-character → more stable

• sp (50%) > sp² (33%) > sp³ (25%)

Acid-Base definitions & Golden Rule

Bronsted-Lowry Acid = proton (H+) donor

Bronstead-Lowery Base = proton acceptor

Golden Rule:

Equilibrium favors WEAKER ACID (higher pKa)

(reaction goes from strong acid → weak acid)

Henderson-Hasselbalch Concept

If pH < pKa → protonated form dominates

If pH > pKa → deprotonated form dominates