4 5 alcohols

Alcohols are colorless liquids that dissolve in water to form neutral solutions.

The first four alcohols are commonly used as fuels. Methanol and ethanol are also used extensively as solvents.

Methanol and ethanol can dissolve many substances that water cannot, such as fats and oils, but can also dissolve most substances that water can dissolve.

Alcohols are named using the same system as alkanes and alkenes, with the final 'e' being replaced with 'ol'.

The name and formula of the first alcohol is methanol, CH3OH.

An organic compound containing a hydroxyl (-OH) group attached to a carbon atom.

A functional group is the specific group of atoms responsible for the characteristic chemical reactions of a compound.

A hydroxyl group is the functional group -OH, consisting of an oxygen atom bonded to a hydrogen atom.

True. It is standard practice to write the functional group on the end when naming alcohols, e.g., CH3OH for methanol.

The name of the alcohol is butanol

Three ways in which ethanol can undergo oxidation:

1. Combustion,
2. Aerobic oxidation,
3. Treatment with an oxidising agent.

The equation for the complete combustion of ethanol is: C2H5OH + 3O2 → 2CO2 + 3H2O

Bacteria in the air (acetobacter) use atmospheric oxygen to oxidise ethanol to ethanoic acid and water: C2H5OH + O2 → CH3COOH + H2O

When ethanol is treated with an oxidising agent, ethanol undergoes oxidation to produce ethanoic acid: CH3CH2OH + [O] → CH3COOH + H2O

During the oxidation of ethanol with potassium dichromate, the potassium dichromate solution turns from orange to green during the reaction.

A chemical reaction in which an element or compound loses electrons, increasing its oxidation state.

Combustion involves a chemical reaction in which a substance reacts with oxygen to release heat and light.

The term aerobic refers to a process or organism that requires the presence of oxygen.

An oxidising agent is a substance that has the ability to oxidise other substances by accepting electrons.

True. Ethanol can be oxidised to produce ethanoic acid, which is the main component of vinegar.

Ethanol can be synthesised by the hydration of ethene.

The conditions required for the hydration of ethene are a temperature of around 300°C, pressure of 60-70 atm, and a concentrated phosphoric acid catalyst.

Ethene is separated first due to its much lower boiling point, then ethanol and water are separated by fractional distillation.

The equation for the hydration of ethene is: CH2=CH2 + H2O → CH3CH2OH

Ethanol is produced by fermentation through yeast enzymes breaking down sugar or starch in the absence of oxygen to produce ethanol and carbon dioxide: C6H12O6 → 2CO2 + 2C2H5OH

A chemical reaction in which a water molecule is added to a compound.

A substance that increases the rate of a chemical reaction without being consumed in the process.

A method of separating a mixture of liquids based on their different boiling points.

A process in which yeast or bacteria convert carbohydrates into alcohol or acids in the absence of oxygen.

False. Fermentation is an anaerobic process that does not require oxygen for ethanol to be produced.