Question

A student takes Na2CO3 powder in a test tube and pours some drops of acetic acid over it. He observes:
(A) no reaction in the test tube
(B) colourless gas with pungent smell
(C) bubbles of a colourless and odourless gas
(D) white fumes with smell of vinegar

Answer 1

(C) bubbles of a colourless and odourless gas

Explanation:

If your pour acetic acid (CH3COOH) over sodium carbonate (Na2CO3) crystals, there is an immediate fizzing as carbon dioxide (CO2) is produced. The reaction will result in a colourless solution of sodium ethanoate. The CO2 produced will be visible by the effervescence seen caused by the escape of the gas. We can prove that the gas produced is carbon dioxide by passing the gas through lime water. The lime water will turn milky.

Na2CO3 + CH3COOH = CH3COONa + CO2 + H2O