Question

Is ammonia more or less dense than air? What property of ammonia is demonstrated by the fountain experiment? Write the correctly balanced equation for the reaction between ammonia and sulphuric acid.

Answer 1

Properties of ammonia $\left({\mathrm{NH}}_3\right)$:

• In laboratory Preparation of Ammonia from Ammonium Chloride $\left({\mathrm{NH}}_4\mathrm{Cl}\right)$, ammonia gas is collected by the downward displacement of air in an inverted gas jar as it is lighter than air and is highly soluble in water.
• Fountain experiment is used to show that ammonia gas is highly soluble in water.

Reaction with acids:

• When ammonia gas or aqueous solution of ammonia (ammonium hydroxide) is treated with acids such as sulphuric acid,${\mathrm{H}}_2{\mathrm{SO}}_4$, it neutralizes acids forming their respective ammonium salts.

Therefore, ammonia is less dense than air. Fountain experiment demonstrates that ammonia gas is highly soluble in water. Balanced equation for the reaction between ammonia and sulphuric acid:

$2{\mathrm{NH}}_3\left(g\right)+{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)⟶{\left({\mathrm{NH}}_4\right)}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)$