Matric chemistry

Definition of organic molecules.

Organic molecules are molecules containing carbon atoms.

Definition of hydrocarbons.

Hydrocarbons are compounds containing only carbon and hydrogen atoms.

Definition of a saturated compound.

A saturated compound is a compound in which all of the bonds between carbon atoms are single bonds.

Definition of an unsaturated compound.

An unsaturated compound is a compound in which there is at least one double and or triple bond between carbon atoms.

Definition of a functional group.

A functional group is an atom or a group of atoms that form the centre of chemical activity in the molecule.

Definition of a homologous series.

A homologous series is a series of similar compounds which have the same functional group and have the same general formula, in which each member differs from the previous one by a single CH2 unit.

Definition of alkanes.

Alkanes contain only single bonds and have the general formula CnH2n plus 2.

Definition of alkenes.

Alkenes contain at least one double bond between two carbon atoms in the chain and have the general formula CnH2n.

Definition of alkynes.

Alkynes contain at least one triple bond between two carbon atoms in the chain and have the general formula CnH2n minus 2.

Definition of structural formula.

Structural formula is a representation in which atoms are shown by their chemical symbols and lines are used to represent all of the bonds between atoms.

Definition of condensed structural formula.

Condensed structural formula represents the way in which atoms are bonded, but not all bond lines are shown.

Definition of molecular formula.

Molecular formula is a chemical formula that indicates the type of atoms and the correct number of each in a molecule.

Definition of structural isomers.

Structural isomers are compounds having the same molecular formula but different structural formulae.

Definition of van der Waals forces.

Van der Waals forces are weak intermolecular forces, with London forces being the weakest type and dipole dipole forces being a stronger type.

Definition of hydrogen bonds.

Hydrogen bonds are strong intermolecular forces found between molecules of NH3, H2O and HF, and also between molecules of alcohols and molecules of carboxylic acids.

Definition of a combustion reaction.

A combustion reaction is an exothermic reaction that transforms chemical potential energy into thermal energy.

Definition of an esterification reaction.

An esterification reaction is an acid catalysed reaction between an alcohol and a carboxylic acid that produces an ester and water.

Definition of catenation.

Catenation is the ability of carbon to make bonds with itself.

Definition of the haloalkane functional group.

The haloalkane functional group is a halogen atom bonded to a saturated carbon atom.

Definition of the alcohol functional group.

The alcohol functional group is a hydroxyl group bonded to a saturated carbon atom.

Definition of the carboxylic acid functional group.

The carboxylic acid functional group is a carboxyl group.

Definition of the ester functional group.

The ester functional group is an ester group.

Definition of chain isomers.

Chain isomers are isomers that have a different type of chain structure, meaning different branching.

Definition of positional isomers.

Positional isomers are isomers that have different positions of the same functional group or alkyl substituent on the parent chain.

Definition of functional isomers.

Functional isomers are isomers that have different functional groups.

Definition of halogenation of an alkane.

Halogenation of an alkane is a substitution reaction in which a hydrogen atom in an alkane is replaced by a halogen atom to form a haloalkane.

Definition of hydrolysis of a haloalkane.

Hydrolysis of a haloalkane is a substitution reaction in which a haloalkane reacts with a hydroxide to form an alcohol.

Definition of hydrogenation.

Hydrogenation is an addition reaction in which hydrogen gas is added across the double bond of an alkene to form an alkane.

Definition of halogenation of an alkene.

Halogenation of an alkene is an addition reaction in which a halogen molecule is added across the double bond of an alkene to form a haloalkane.

Definition of hydrohalogenation.

Hydrohalogenation is an addition reaction in which a hydrogen halide is added across the double bond of an alkene to form a haloalkane.

Definition of hydration of an alkene.

Hydration of an alkene is an addition reaction in which water is added across the double bond of an alkene to form an alcohol.

Definition of dehydrohalogenation.

Dehydrohalogenation is an elimination reaction in which a hydrogen halide is removed from a haloalkane to form an alkene.

Definition of dehydration of an alcohol.

Dehydration of an alcohol is an elimination reaction in which water is removed from an alcohol to form an alkene.

Definition of cracking.

Cracking is the breaking up of large alkane molecules to form a mixture of smaller and more useful alkane and alkene molecules.

Definition of thermal cracking.

Thermal cracking is cracking that takes place at high pressures and temperatures without a catalyst.

Definition of catalytic cracking.

Catalytic cracking is cracking that takes place at lower temperatures and pressures in the presence of a catalyst.

Prefix for amount of groups of a given functional group: 2

Di-

Prefix for amount of groups of a given functional group: 3

Tri-

Prefix for amount of groups of a given functional group: 4

Tetra-

Prefix for substituent alkyl group of length: 1 carbon

Methyl

Prefix for substituent alkyl group of length: 2 carbons

Ethyl

Base name for parent chain with this many carbon atoms: 1

Meth

Base name for parent chain with this many carbon atoms: 2

Eth

Base name for parent chain with this many carbon atoms: 3

Prop

Base name for parent chain with this many carbon atoms: 4

But

Base name for parent chain with this many carbon atoms: 5

Pent

Base name for parent chain with this many carbon atoms: 6

Hex

Base name for parent chain with this many carbon atoms: 7

Hept

Base name for parent chain with this many carbon atoms: 8

Oct

Shape of functional group of alkane

Shape of functional group of alkene

Shape of functional group of alkyne

Shape of functional group of haloalkane

Shape of functional group of alcohol

Shape of functional group of carboxylic acid

Shape of functional group of ester

Name ending for functional group: alkane

-ane

Name ending for functional group: alkene

-ene

Name ending for functional group: alkyne

-yne

Name ending for functional group: haloalkane

-ane

Name ending for functional group: alcohol

-an- -ol (number)

Name ending for functional group: carboxylic acid

-anoic acid

Name ending for functional group: ester

-anoate

General formula of alkane

CnH2n+2

General formula of alkene

CnH2n

How does ester naming work

(length of alcohol)-yl- -(length of carboxylic acid)-anoate

How does drawing an ester work?

The carboxylic (second word in the name) length of carbons gets the double bonded oxygen

The alcohol length get no double bonded oxygen and is saturated aside from the oxygen

Explain why the type of functional group is relevant to understanding the nature of the organic molecule.

Non polar molecules such as hydrocarbons (alkanes, alkenes and alkynes) only have weak van der Waals dispersion forces between molecules. Haloalkanes and esters are polar molecules with dipole-dipole forces between molecules, which are stronger than dispersion forces. Alcohols and carboxylic acids form strong hydrogen bonds between molecules, with the hydrogen bonds between carboxylic acid molecules being stronger than those between alcohol molecules, and this is why alcohols and carboxylic acids mix well with water.

Explain why the number of functional groups is relevant to understanding the nature of the organic molecule.

Hydrocarbons only have weak van der Waals London forces between molecules, but carboxylic acids and alcohols have strong hydrogen bonds between molecules. A molecule with more functional groups capable of hydrogen bonding has more hydrogen bonds between molecules, so the melting and boiling points of alcohols and carboxylic acids increase as the number of these functional groups increases, and are higher than those of similar sized hydrocarbons.

Explain why chain length and molecular mass are relevant to understanding the nature of the organic molecule.

Longer chain molecules and molecules with a larger molecular mass have stronger intermolecular forces than shorter or smaller molecules, so they have higher melting and boiling points.

Explain why branched chains are relevant to understanding the nature of the organic molecule.

Branched chain molecules are more spherical in shape than straight chain molecules, so they have a smaller surface contact area between molecules. This results in weaker intermolecular forces, so branched chains have lower melting and boiling points than straight chains of the same molecular formula.

What reactions do the following conditions produce: an alkane reacting with a halogen, in the presence of UV light or heat?

Halogenation of an alkane

What reactions do the following conditions produce: a haloalkane reacting with a base, heated under reflux in a dilute alkali solution?

Hydrolysis

What reactions do the following conditions produce: an alkene reacting with hydrogen gas, dissolved in an organic solvent with a Pt, Ni or Pd catalyst, in a hydrogen atmosphere?

Hydrogenation

What reactions do the following conditions produce: an alkene reacting with a halogen at room temperature?

Halogenation of an alkene

What reactions do the following conditions produce: an alkene reacting with a hydrogen halide, with no water present?

Hydrohalogenation

What reactions do the following conditions produce: an alkene reacting with water, using steam and a catalyst such as H3PO4?

Hydration

What reactions do the following conditions produce: a haloalkane heated with a hot concentrated KOH or NaOH solution in an ethanol solvent, with no water present?

Dehydrohalogenation

What reactions do the following conditions produce: an alcohol heated with excess concentrated H2SO4 or H3PO4?

Dehydration

What reactions do the following conditions produce: a large hydrocarbon molecule broken down at high pressure and temperature, without a catalyst?

Thermal cracking

What reactions do the following conditions produce: a large hydrocarbon molecule broken down at lower pressure and temperature, with a catalyst?

Catalytic cracking

What reactions do the following conditions produce: an alcohol reacting with a carboxylic acid, with an acid catalyst and gentle heating?

Esterification

What reactions do the following conditions produce: a hydrocarbon reacting with excess oxygen?

Combustion

What is halogenation of an alkane, and what are its conditions?

A hydrogen atom of the alkane is replaced by a halogen atom. Conditions: UV light or heat is needed.

What is hydrolysis, and what are its conditions?

The hydroxyl group from a base replaces the halogen atom of a haloalkane. Conditions: heat under reflux in a dilute alkali solution.

What is hydrogenation, and what are its conditions?

Hydrogen gas is added to an alkene, also known as oil hardening and used in margarine production. Conditions: the alkene is dissolved in an organic solvent, with a Pt, Ni or Pd catalyst added, in a hydrogen atmosphere.

What is halogenation of an alkene, and what are its conditions?

A halogen molecule is added to an alkene molecule. Conditions: occurs readily at room temperature, and forms the basis of the bromine test for unsaturation.

What is hydrohalogenation, and what are its conditions?

A hydrohalogen is added to an alkene. Conditions: no water may be present.

What is hydration, and what are its conditions?

Water is added to an alkene. Conditions: steam and a catalyst, such as H3PO4, are added.

What is dehydrohalogenation, and what are its conditions?

Hydrogen and a halide are removed from a haloalkane. Conditions: a hot concentrated KOH or NaOH solution in an ethanol solvent, meaning water is absent.

What is dehydration, and what are its conditions?

Water is removed from an alcohol. Conditions: acid catalysed dehydration, heating the alcohol with excess concentrated H2SO4 or H3PO4.

What is cracking, and what are its conditions?

The breaking up of large hydrocarbon molecules into smaller molecules. Conditions: thermal cracking uses high pressure and temperature without a catalyst, while catalytic cracking uses lower pressure and temperature with a catalyst.

What is esterification, and what are its conditions?

An acid catalysed reaction between an alcohol and a carboxylic acid that produces an ester and water. Conditions: an acid catalyst and gentle heating.

What is combustion, and what are its conditions?

An exothermic reaction that transforms chemical potential energy into thermal energy, in which a substance burns in oxygen and releases energy and a gas. Conditions: excess oxygen is needed for complete combustion.

What are all the specific reactions under the following general organic chemical reaction: substitution reactions?

Halogenation, which converts an alkane to a haloalkane, and hydrolysis, which converts a haloalkane to an alcohol.

What are all the specific reactions under the following general organic chemical reaction: addition reactions?

Hydrogenation, halogenation of an alkene, hydrohalogenation, and hydration.

What are all the specific reactions under the following general organic chemical reaction: elimination reactions?

Dehydrohalogenation, dehydration, and cracking.

What general reaction type does the following reaction fall under: hydrolysis?

Substitution

What general reaction type does the following reaction fall under: hydrogenation?

Addition

What general reaction type does the following reaction fall under: hydrohalogenation?

Addition