Trig rules (Quick)

IR Stretching Frequencies

TRICK!!!!!!!!!!!!!!!

***"CARBOXYLIC ACID" group is in same range as O-H but even BROADER!! (3500-2500)

Trends:

3600 - 2700 cm-1	X-H
2700 - 1900 cm-1	X=Y
1900 - 1500 cm-1	X=Y
1500 - 500 cm-1	X-Y

**Add AROMATIC ranges:

Aromatic C-H Stretch Aromatic C-H Bending Aromatic C=C Bending

~3030 (v) 860 - 680 (s) 1700 - 1500 (m,m)

1) More thorough TABLE: http://www.chem.ucla.edu/~webspectra/irtable.html

2) Explanation: http://www.chem.ucla.edu/~webspectra/irintro.html

3) Practice Problems: http://www.chem.ucla.edu/~webspectra/

Acidity/Basicity of Functional Groups

Acidity

Basicity

Ortho/Meta/Para Directors

Electron Donating = Activating (Ortho, Para) (HAS LONE PAIR OF ELECTRONS, FORMS RESONANCE STRUCTURES!)

- participates in electrophilic substitution reactions

EX: -NH2, -OH, -OR (there's lone pair on the nitrogen/oxygen)
Strong: Anything that has lone pair w/o a group of carbonyl.
EX: -OR
Moderate: They have a C=O (carbonyl)
EX: -NHCOR
Weak: All alkyl group because they donate in electron density.

Electron Withdrawing = Deactivating (Meta, Halogens) (USUALLY POSITIVE, NO LONE PAIR ELECTRONS)

- removes electron density from the benzene ring, making electrophilic aromatic substitution reactions slower and more complex relative to benzene

-NO2, -NH3+ (there's no lone pair on the nitrogen)
STRONG: there's no lone pair, no carbonyl group
EX: -CN, -NO2
MODERATE: carbonyl, but no lone pair
Ex: -COH, -CO2H
WEAK:
Deactivating: o,p directors
These are all HALOGENS.

ATOMIC TRENDS

(atomic radius)

(attract electrons to itself)

Acids & Bases

Strong Acids

Hydroiodic acid	HI
Hydrobromic acid	HBr
Hydrochloric acid	HCl
Perchloric acid	HClO4
Sulfuric acid	H2SO4
Nitric acid	HNO3

Strong Bases

Group 1 hydroxides	NaOH, LiOH, KOH
Group 1 oxides	Li2O, etc.
Some group 2 hydroxides	Ba(OH)2, Sr(OH)2, Ca(OH)2
Metal amides	NaNH2, LiNH2, Mg(NH2)2, Ca(NH2)2, etc.

- The conjugate base of a strong acid has no basic properties in water.

- The conjugate base of a weak acid is a weak base.

- The conjugate acid of a strong base has no acidic properties in water. For example, the conjugate acid of LiOH is Li+, which does not act as an acid in water.

- The conjugate acid of a weak base is a weak acid (and the weaker the base, the stronger the conjugate acid). For ex, the conjugate acid of NH3 is NH4+, a weak acid.

Amphoteric: can act as either an ACID or BASE. The conjugate base of a weak polyprotic (more than one H) acid is always amphoteric, because it can either donate or accept another proton.

- ex: H₂CO₃ à HCO₃^- à CO₃^2-

Reaction Rate

1. the lower the activation energy, the faster the reaction rate

2. the greater the concentrations of the reactants, the faster the rate (more favorable collisions)

3. the higher the temperature of the reaction mixture, the faster the reaction rate

ΔG has no bearing on rate of the reaction!

Thermodynamic & Kinetic factors DO NOT AFFECT EACH OTHER!!!

Catalyst - lowers the activation energy of the rate-determining step (therefore the energy of the higher-energy transition state), remains UNCHANGED at the end of the rxn

***even though the catalyst MAY physically change in the middle...will always revert back for no net change

Rate Law - reactants of rate-determining step, NOT products...(previous post)...can only be determined EXPERIMENTALLY