Chemical Properties of Carboxylic Acids

1. Ethanoic acid is a weak monoprotic acid. As such, its chemical properties are similar to acids such as hydrochloric acid, nitric acid and sulphuric acid.
2. Ethanoic acid can react with:
1. base
2. metal carbonate
3. metal
4. alcohol

Reactions of Carboxylic Acids with Reactive Metals

Carboxylic acids react with the more reactive metals to produce a salt and hydrogen.

Example:

CH₃COOH + Zn → Zn(CH₃COO)₂ + H₂

CH₃COOH + Ca → Ca(CH₃COO)₂ + H₂

HCOOH + Mg → Mg(HCOO)₂ + H₂

Reactions of Carboxylic Acids with Carbonates

As other acids, carboxylic acids react with carbonate metal to produce a salt, water and carbon dioxide.

Example:

HCOOH + Na₂CO₃ → HCOONa + CO₂ + H₂O

CH₃COOH + CaCO₃ → Ca(CH₃COO)₂ + CO₂ + H₂O

Neutralisation

As other acids, carboxylic acids react with base oxide or alkali to produce salt and water.

Example:

HCOOH + CaO → Ca(HCOO)₂ + H₂O

CH₃COOH + NaOH → CH₃COONa + H₂O

CH₃COOH + Al₂O₃ → Al(CH₃COO)₃ + H₂O

Esterification

Carboxylic acid reacts with alcohol with the presence of .concentrated sulphuric acid as catalyst to produce ester and water.

Example:
CH₃COOH + C₂H₅OH → CH₃COOC₂H₅ + H₂O

CH₃COOH + CH₃OH → CH₃COOCH₃ + H₂O

1. The concentrated sulphuric acid acts as
1. a drying agent to absorb the water that is produced
2. a catalyst
2. The reactant mixture needs to be heated under reflux.

Preparing of Propyl Ethanoate (ester) in Laboratory

1. Propyl ethanoate, CH₃COOC₂H₅ can be prepared in the laboratory by heating a mixture of propanoic acid and ethanol, with concentrated sulphuric acid under reflux.
2. The mixture is heated under reflux to prevent the alcohol and propyl ethanoate to evaporate and escape to the surrounding.
3. The mixture is heated in a water bath:
1. to maintain temperature so that the temperature is not too high
2. to ensure uniform heating