chem organics

What is a hydrocarbon?

A compound containing hydrogen and carbon only.

What is an empirical formula?

The simplest whole-number ratio of atoms in a compound.

What is a molecular formula?

The actual number of each type of atom in a molecule.

What is a general formula?

A formula showing the composition of every member of a homologous series.

What is a structural formula?

A formula showing how atoms are arranged in a molecule.

What is a displayed formula?

A formula showing every atom and every covalent bond.

What is a homologous series?

A family of compounds with the same functional group and similar chemical reactions.

What is a functional group?

An atom or group of atoms responsible for a compound's reactions.

What is isomerism?

Compounds have the same molecular formula but different structural formulae.

What does IUPAC nomenclature provide?

A systematic method for naming organic compounds.

What are the prefixes for 1 to 6 carbon atoms?

Meth-, eth-, prop-, but-, pent-, hex-.

What does the suffix -ane indicate?

An alkane.

What does the suffix -ene indicate?

An alkene.

What does the suffix -ol indicate?

An alcohol.

What does the suffix -oic acid indicate?

A carboxylic acid.

What is a substitution reaction?

One atom or group is replaced by another atom or group.

What is an addition reaction?

Atoms add across a multiple bond to form one product.

What is combustion?

A reaction with oxygen that releases heat energy.

What is crude oil?

A mixture of hydrocarbons.

How is crude oil separated?

By fractional distillation.

Why can crude oil be separated by fractional distillation?

Its hydrocarbons have different boiling points.

What happens during fractional distillation?

Hydrocarbons vaporise and condense at different temperatures.

What are fractions?

Groups of hydrocarbons with similar boiling points and properties.

What are the six main crude oil fractions?

Refinery gases, gasoline, kerosene, diesel, fuel oil and bitumen.

What is refinery gas used for?

Heating and cooking.

What is gasoline used for?

Fuel for cars.

What is kerosene used for?

Fuel for aircraft.

What is diesel used for?

Fuel for diesel engines and vehicles.

What is fuel oil used for?

Fuel for ships and power stations.

What is bitumen used for?

Road surfacing and roofing.

How does colour change down the crude oil fractionation column?

It generally becomes darker.

How does boiling point change down the crude oil fractionation column?

It increases.

How does viscosity change down the crude oil fractionation column?

It increases.

What is a fuel?

A substance that releases heat energy when burned.

What are the products of complete combustion of hydrocarbons?

Carbon dioxide and water.

What are the possible products of incomplete combustion?

Carbon monoxide, carbon and water.

Why is carbon monoxide poisonous?

It reduces the blood's capacity to transport oxygen.

Why do nitrogen oxides form in car engines?

High temperatures cause nitrogen and oxygen from air to react.

What impurity in fuels forms sulfur dioxide?

Sulfur-containing impurities.

How does sulfur dioxide contribute to acid rain?

It reacts with water and oxygen to form acidic substances.

How do nitrogen oxides contribute to acid rain?

They react with water and oxygen to form acidic substances.

What is catalytic cracking?

Breaking long-chain alkanes into shorter alkanes and alkenes.

What catalyst is used for catalytic cracking?

Silica or alumina.

What temperature is used for catalytic cracking?

600 to 700 C.

Why is cracking necessary?

It produces more useful fractions to match supply with demand.

What is the general formula for alkanes?

CnH2n+2.

Why are alkanes saturated hydrocarbons?

They contain only single carbon-carbon bonds.

What is methane's formula?

CH4.

What is ethane's formula?

C2H6.

What is propane's formula?

C3H8.

What is butane's formula?

C4H10.

What is pentane's formula?

C5H12.

What is the first alkane with structural isomers?

Butane.

What are the two isomers of butane?

Butane and 2-methylpropane.

How do alkanes react with halogens?

They undergo substitution in ultraviolet radiation.

What condition is needed for alkane-halogen substitution?

Ultraviolet radiation.

What type of substitution is required for this specification?

Mono-substitution.

What is the functional group of an alkene?

C=C.

What is the general formula for alkenes?

CnH2n.

Why are alkenes unsaturated hydrocarbons?

They contain a carbon-carbon double bond.

What is ethene's formula?

C2H4.

What is propene's formula?

C3H6.

What are the unbranched C4 alkene isomers?

But-1-ene and but-2-ene.

What happens when an alkene reacts with bromine?

A dibromoalkane is formed.

What is bromine water used to test for?

An alkene.

What happens to bromine water with an alkene?

It changes from orange/brown to colourless.

What happens to bromine water with an alkane?

No change without UV radiation.

What is the functional group of an alcohol?

-OH.

What is methanol's formula?

CH3OH.

What is ethanol's formula?

C2H5OH.

What is propan-1-ol's formula?

C3H7OH.

What is butan-1-ol's formula?

C4H9OH.

What are the three ways ethanol can be oxidised?

Combustion, microbial oxidation and heating with acidified potassium dichromate(VI).

What is produced when ethanol burns completely?

Carbon dioxide and water.

What is produced when ethanol is oxidised by oxygen in air?

Ethanoic acid.

What is produced when ethanol is heated with acidified potassium dichromate(VI)?

Ethanoic acid.

How is ethanol made from ethene?

React ethene with steam using phosphoric acid catalyst at about 300 C and 60 to 70 atm.

How is ethanol made by fermentation?

Glucose is fermented using yeast enzymes without air.

What temperature is used for fermentation?

About 30 C.

Why is fermentation carried out without air?

Yeast produces ethanol anaerobically.

Why must fermentation use an optimum temperature?

Too high denatures enzymes; too low slows the reaction.

What is the functional group of a carboxylic acid?

-COOH.

What is methanoic acid's formula?

HCOOH.

What is ethanoic acid's formula?

CH3COOH.

What is propanoic acid's formula?

C2H5COOH.

What is butanoic acid's formula?

C3H7COOH.

What happens when a carboxylic acid reacts with a metal?

A salt and hydrogen are produced.

What happens when a carboxylic acid reacts with a metal carbonate?

A salt, water and carbon dioxide are produced.

What acid is found in vinegar?

Ethanoic acid.

What is vinegar?

An aqueous solution containing ethanoic acid.

What is the functional group of an ester?

-COO-.

What ester forms from ethanol and ethanoic acid?

Ethyl ethanoate.

What is needed to make an ester from an alcohol and carboxylic acid?

An acid catalyst.

What is the reaction between an alcohol and carboxylic acid called?

Esterification.

What are esters like?

Volatile compounds with distinctive smells.

What are esters used for?

Food flavourings and perfumes.

What is the structural formula of ethyl ethanoate?

CH3COOCH2CH3.

Which alcohol forms the ethyl part of an ester?

Ethanol.

Which acid forms the ethanoate part of ethyl ethanoate?

Ethanoic acid.

How can you identify the alcohol in an ester name?

The first part gives the alcohol-derived group.