Reactants: An alcohol (e.g. ethanol), a hydrogen halide (e.g. HBr)
Products: a HalogenoAlkane (e.g. bromoethane), water
Conditions: no special
C₂H₅OH + HBr → C₂H₅Br + H₂O

Conditions: Acidified Potassium Dichromate(VI) or Sodium Dichromate(VI) is used as an oxidising agent. Reaction occurs in reflux.

The products that form from oxidation depend on the structure of the alcohol.

The oxidation of the primary alcohol, ethanol with Cr₂O₇^2- / H⁺ is as follows: CH₃CH₂OH + [O] → CH₃CHO (the aldehyde; ethanal)

Remember: Oxidation is defined as the gain of Oxygen AND/OR the loss of hydrogen.

Primary alcohols: oxidise to aldehydes and then to carboxylic acids
Secondary alcohols: Oxidise to ketones
Tertiary alcohols: Cannot be oxidised

(Complete) Combustion of any alcohol produces carbon dioxide and water.
Burning completely in an excess of oxygen
C₂H₅OH + 3 O₂ → 2 CO₂ + 3 H₂O

However, incomplete combustion can occur when oxygen is not in excess (lack of oxygen) which can cause carbon monoxide (CO) or even carbon residue (C) to form as the products.

Remember the basic principle:

ACID + ALCOHOL → ESTER + WATER

An alcohol (e.g. ethanol) + a carboxylic acid (e.g. ethanoic acid) → an ester (e.g. ethyl ethanoate) and water
Conditions: H₂SO₄ (sulfuric acid) Catalyst

Reactants: An alcohol
Products: Alkene + water
Conditions: hot and concentrated sulfuric acid

An alcohol can be formed by the hydration of the alkene; ethene, shown below:
CH₂=CH_2(g) + H₂O_(g) → CH₃CH₂OH_(g)
Conditions: 300 degrees Celsius
60 atm pressure
H₃PO₄ (phosphoric acid) catalyst.