Question

A student takes 2 mL acetic acid in a dry test tube and adds a pinch of sodium hydrogen carbonate to it. He makes the following observations:

I. A colourless and odourless gas evolves with a brisk effervescence.

II. The gas turns lime water milky when passed through it.

III. The gas burns with an explosion when a burning splinter is brought near it.

IV. The gas extinguishes the burning splinter that is brought near it.

The correct observations are:

(A) I, II, and III

(B) II, III and IV

(C) III, IV and I

(D) IV, I and II

Answer 1

(D)

When 2 mL acetic acid is taken in a dry test tube and a pinch of sodium hydrogen carbonate is added to it, a colourless and odourless gas evolves with a brisk effervescence which is CO₂.

When CO₂ is passed through lime water it turns lime water milky.

CO₂ also extinguishes the burning splinter when it is brought near it.