Question

Question: Give the IUPAC name for each metal salt of a carboxylate anion.

a.

b.

c.

d.

Short answer

Answer

a. Lithium benzoate

b. Sodium formate or sodium methanoate

c. Potassium 2-methylpropanoate

d. Sodium 4-bromo-6-ethyloctanoate

Step-by-step solution

Step-by-Step Solution Step 1: Metal salt of carboxylic acid

Carboxylic acid salts are also formed when acids react with bases. Carboxylic acids react with more reactive metals to form metal salt and hydrogen.

The general formula for the salt formed during this reaction is where n is the valency of the metal ion.

These metal salts are water-soluble and are used to separate the acids from organic mixtures

Nomenclature of metal salts

The suffix ‘oic acid’ is replaced with ‘oate’ to name the carboxylate ion of a carboxylic acid.

The metal ion in the salt is named first, followed by the name of the carboxylate ion.

Therefore, to name a metal salt, put the following three parts together:

The common name of the parent chain is used to obtain the common name of the metal salt.

Naming of given metal salts

a. The metal in the salt is lithium. The carboxylate ion is the conjugate base of benzoic acid.

Therefore, the IUPAC name of the metal salt is lithium benzoate.

b. The metal in the salt is sodium. The carboxylate ion is the conjugate base of methanoic acid.

Therefore, the IUPAC name of the metal salt is sodium methanoate.

The common name for methanoic acid is formic acid. Therefore, the common name for the metal salt is sodium formate.

c. The metal in the salt is potassium. The carboxylate ion is the conjugate base of 2-methylpropanoic acid.

Therefore, the IUPAC name of the metal salt is potassium 2-methylpropanoate.

d. The metal in the salt is sodium. The carboxylate ion is the conjugate base of 4-bromo-6-ethyloctanoic acid.

Therefore, the IUPAC name of the metal salt is sodium 4-bromo-6-ethyloctanoate