Summary Notes: Module 4: Core Organic Chemistry: Chemistry OCR A A Level

Hydrocarbons

A compound containing carbon and hydrogen only.

Saturated

Has single bonds only.

Unsaturated

Contains carbon-carbon multiple bonds.

Homologous Series

A series of organic compounds having the same functional group but with each successive member differing by a CH2.

Functional Group

Part of molecule largely responsible for molecule’s chemical properties.

Aliphatic

Carbon atoms joined in unbranched/branched chains, or non aromatic rings.

Acyclic

An aliphatic compound arranged in non-aromatic ring, with without branches.

Aromatic

Some/all carbon atoms found in a benzene ring.

Alkyne

Contains at least one triple carbon-carbon bond.

Molecular Formula

Shows number of + type of atoms of each element in a molecule.

e.g. C2H6O.

Empirical Formula

Simplest whole number ratio of atoms of each element present in a compound.

e.g. C4H8 → CH2

General Formula

Simplest algebraic formula for any member of a homologous series.

Displayed Formula

Shows relative positioning of all the atoms in a molecule and the bonds between them.

Structural Formula

Uses the smallest amount of detail necessary to show the arrangement of atoms in a molecule.

Structural Isomers

Compounds with same molecular formula but different structural formula, can have same functional group at different point/different functional group.

Homolytic Fission

Each of the covalently bonded atoms takes one of the shared electrons, forms 2 radicals.

Heterolytic Fission

One of covalently bonded atoms takes both the electrons, one becomes -ve ion and one becomes +ve ion.

Addition

Two reactants join to make one product.

Substitution

Atom or group of atoms is replaced by a different atom/group of atoms.

Elimination

Removal of a small molecule from a larger molecule.

Sigma Bond

The result of overlapping of 2 orbitals, one from each bonding atom, positioned on line directly between bonding atoms.

Stereoisomers

Have same structural formula but a different arrangement atoms in space.

Cis-trans

A type of E/Z isomerism where one of groups on each carbon must be a hydrogen.

Cahn-ingold-Prelog Rules

Groups of higher priority same side double bond=Z, groups of higher priority diagonally placed=E. highest priority determined by Mr of atoms attached directly to carbons in double bond (if atom is same, go along chain until 1st different).

Electrophile

An electron pair acceptor (usually a +ve ion or a molecule with atom with δ+ charge).

Poly(propene) used for?

Toys, guttering, windows etc.

Poly(phenylethane)

Packaging material/food trays + cups.

Poly(tetrafluoroethene)

Coating non-stick pans, cable insulation.

Recycling

Conserves fossil fuels + decreases waste going in landfill. Have to be sorted by type, chopped into flakes, washed, dried, melted then cut into pellets + used to make new products.

Bioplastics

Produced from plant starch, cellulose, plant oils + proteins- renewable & sustainable (protects environment & conserves oil reserves).

Biodegradable Polymers

Broken down by microorganisms into water, carbon dioxide + biological compounds. Can be used as bin liners for food waste so both compost.

Photodegradable Polymers

(Oil based) contain bonds weakened by absorbing light to start degradation OR light absorbing additives used.

Nucleophile

An electron pair donor.

Hydrolysis

A chemical reaction involving water/aq solution of a hydroxide causing breaking of a bond in a molecule.