Alcohols

What are alcohols?

Organic compounds containing the –OH functional group.

What is the functional group of an alcohol?

–OH (hydroxyl group).

What is the general formula of saturated monohydric alcohols?

CₙH₂ₙ₊₁OH.

What is the molecular formula of methanol?

CH₃OH.

What is the molecular formula of ethanol?

C₂H₅OH.

What is the molecular formula of propanol?

C₃H₇OH.

What is the molecular formula of butanol?

C₄H₉OH.

What is the structural formula of ethanol?

CH₃CH₂OH.

Why are alcohols considered a homologous series?

They have the same functional group, similar chemical properties and successive members differing by CH₂.

What happens when alcohols undergo complete combustion?

They form carbon dioxide and water.

What is the word equation for complete combustion of ethanol?

Ethanol + oxygen → carbon dioxide + water.

What is the balanced equation for complete combustion of ethanol?

C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O.

Why can alcohols be used as fuels?

They release energy during combustion.

What happens when alcohols react with sodium?

They produce a sodium alkoxide and hydrogen gas.

What gas is produced when ethanol reacts with sodium?

Hydrogen.

How can the hydrogen produced be identified?

A lit splint produces a squeaky pop.

What happens when an alcohol is oxidised?

It may form a carboxylic acid, depending on the alcohol's structure and conditions.

What happens when ethanol is oxidised using a suitable oxidising agent?

It forms ethanoic acid.

What is a common use of ethanol?

It is used as a solvent, fuel and chemical feedstock.

Why is ethanol useful as a solvent?

It can dissolve many substances that are not readily soluble in water.