Tends to inhibit the van der Waals forces by reducing the surface area available for intermolecular reaction.

Reduces attractive foraces between molecules and lowers both melting and boiling point.

The greater the molecular weight, the greater the surface area to interact, the greater the van der Waal's forces.

Higher melting and boiling points.

Occurs between a hydrogen bond donor (F,O,N) and a hydrogen bond acceptor (a lone pair of e's on a nitrogen, oxygen or flourine in another molecule).

The more donors and acceptors in a molecule, the higher the MP and BP.

(Carbonium Ions)

Positively charged species with a full positive charge on carbon.

Reactivity is based on which carbon bears the charge.

Will always be sp2 hybridized on the MCAT

Reaction intermediates that contain one unpaired electron.

Reactivity is based on which carbon bears the negative charge.

Will be sp2 on the MCAT with the unpaired electron in the p orbital.

Negatively charged species with a full negative charge localized on carbon.

Reactivity is based on which carbon bears the negative charge.

On the MCAT it will be sp2 hybridized with the lone pair in an unhybridized p orbital OR it may be sp3 hybridized with the lone pair in an sp3-hybridized orbital.

methyl-->1^o-->2^o-->3^o

3^o-->2^o-->1^o-->methyl

Donate electron density away from themselves through sigma bonds.

Alkyl groups will always be electron-donating on the MCAT.

A system containing three or more atoms that each bear a p orbital.

These orbitals are aligned so that they are all parallel, creating a possibility of delocalized electrons.

Electrons that are allowed to interact with orbitals on adjacent atoms and are no longer confined to their orginal "space"

The electron density is spread out.

Alcohol with the H removed.

Very reactive since the electrons on the O have no adjacent p orbital or pi system.

Alkoxide ion is thus a strong base.

Electrons on the negatively charged oxygen are adjacent to the pi bond and thus delocalized.

This leads to greater stability and thus higher acidity of the conjugate acid.

Remove the H and create the resulting base.

Whichever base is more stable is the stronger acid.

If resonance leave a negative charge on C, this is less stable than on electronegative O.

Arises when bond angles between ring atoms deviate from the ideal angle predicted by the hybridization of the atoms.

Hydrogenating these cycloalkenes with angle strain over metal causes them to break open into single stranded alkanes.