Apparatus: Test tube, glass rod, beaker, Bunsen burner, etc.
Chemicals: Hydrochloric acid, ammonia solution, magnesium strip, quick lime, etc.
Activity 1: 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 the top of the test tube. You will observe a white smoke emanating from the tip of the glass rod. What must have happened?

Explanation

When hydrochloric acid in test tube is heated, HCI vapours come out of the test tube. When the glass rod dipped in ammonia is brought near the mouth of the test tube, hydrogen chloride gas and ammonia gas react to form the salt, ammonium chloride in gaseous state. It immediately undergoes condensation process at room temperature and is transformed into the solid state. Hence, a white smoke is observed to be emanating from the tip of the glass rod.
`underset("Ammonia")(NH_(3)(g))+underset("Hydrogen chloride" )(HCl_((g)))rarrunderset("Ammonium chloride")(NH_(4)Cl_((s))`