Question

Take a small amount of hydrochloric acid in a test tube . Heat the test
tube . Dip a glass rod in the ammonia solution and hold on top of the test
tube . You will observe a white smoke emanating from the tip of the glass
rod.

Answer the following:

i) State the type of chemical reaction. Write the chemical equation for the
above activity.

ii) Explain what lead to the formation of white smoke from the tip of the glass rod.​

Answer 1

1. i.Due to heating HCl vapours started coming out from the test tube, and NH3 gas came out from the solution on the glass rod.

ii. The ammonia gas and hydrogen chloride gas reacted to from the salt ammonium chloride in 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. NH3(g)Ammonia+HCl(g)Hydrogen Chloride→NH4Cl(s)Ammonium chloride

3. It is a combination reaction.