The major product formed by the reaction between ethanoic acid and aqueous sodium hydroxide is

Analyze the question: Ethanoic acid (CH₃COOH) is a carboxylic acid. Sodium hydroxide (NaOH) is a strong base. An acid and a base react in a neutralisation reaction, producing a salt and water.

Concept: Carboxylic acid + alkali → salt + water. The salt's name comes from the acid: ethanoic acid gives an ethanoate, and the metal from the base (sodium) gives the first part of the name.

Solution:

CH₃COOH + NaOH → CH₃COONa + H₂O

• CH₃COONa is sodium ethanoate (the salt).
• H₂O is water (the by-product).

Checking the options:

• A. Soap: this is made by saponification, which is the reaction of fats or oils with NaOH. Ethanoic acid is not a fat or oil, so this is wrong.
• B. Sodium ethanoate: this is the salt formed, so it is correct.
• C. Sodium methoxide: this is CH₃ONa, formed from methanol and sodium. It is not formed here.
• D. Water: this is also formed, but it is a by-product. The question asks for the major product in the sense of the organic product, which is the salt.

Answer: B. Sodium ethanoate

Exam tip: In acid-base questions, always remember "acid + base → salt + water". Name the salt as metal + acid-stem + "-oate" for carboxylic acids (ethanoic acid → ethanoate, methanoic acid → methanoate). Also remember that soap comes only from fats and oils plus alkali.