Question

Read the text below and answer the questions that follow:

A small amount of hydrochloric acid was taken in a test tube. The test tube was heated. A glass rod was dipped in the ammonia solution and held on the top of the test tube. A white smoke was seen emanating from the tip of the glass rod.

1. What must have happened?
2. Which colour of gas is formed?
3. Write the chemical equation for the reaction.

Answer 1

1. Due to heating, HCl vapours started coming out from the test tube, and NH₃ gas came out from the solution on the glass rod. The ammonia gas and hydrogen chloride gas reacted to form the salt ammonium chloride in the gaseous state first, but immediately due to the condensation process at room temperature, it got transformed into the solid state.
2. As a result white smoke was formed.
3. The chemical equation for this is as follows:
   \[\ce{\underset{Ammonia}{NH3(g)} + \underset{Hydrogen chloride}{HCl(g)} -> \underset{Ammonium chloride}{NH4Cl(s)}}\]