NCEA Level 3 - Organic

Optical isomer (enantiomers)

a compound which have the same structure but are mirror images of each other and typically differ in optical activity.

Chiral Compound

a molecule that cannot be superimposed on its mirror image

What does a chiral compound require

It requires four different groups bonded to a carbon

Chiral compound chemical properties

They have the same chemical properties because they have the same functional group

Optical isomers differences

they will rotate plane polarised light in opposite directions by the same amount

Addition reaction

involve 2 (or more in the case of polymers) molecules combining to make one molecule. Occurs when double bonds are broken to form a single c-c bond, and 2 new covalent bonds

Markovnikov’s rule

When adding HX or H20 to an asymmetric alkene, the H will form a bond with the carbon of the double bond with the greatest number of H’s already attached

Substitution reaction

Where one group/atom is exchanged for another atom/group

Elimination reaction

A molecule goes from saturated to unsaturated by removing the functional group and H from an adjacent atom (will always yield an alkene)

Zaitsev’s rule

With an asymmetric haloalkane or alcohol, the H is preferentially lost from the adjacent Carbon with the fewest H’s attached.

Reflux

As many organic compounds have a low b.p, they are volatile and will evaporate before a reaction can occur. The condenser will condense the vapour and return it to the reaction vessel. This ensures the reaction can occur under heating with out losing product or reactants (keep yield high)

Distillation

Used to seperate organic molecules which have different b.p. The lower b.p substance will be removed first as it boils off. It then cools in a condenser and reverts to a liqud where it is collected.

What happens to a primary alcohol when oxidised

it becomes an aldehyde, then a carboxylic acid

What happens to a secondary alcohol when oxidised

it becomes a ketone

What happens to a tertiary alcohol when oxidised

nothing

Hydrolysis

breaking of a molecule using water. Involves the addition of water with an acid or base