Question

A gas (M) burns in Hydrogen to form another gas (N) which forms dense white fumes with Ammonia. Name M and N. Also write down the chemical changes involved.

Answer 1

• The gas M is Chlorine $\left({\mathrm{Cl}}_2\right)$ and gas N is Hydrogen chloride $\left(\mathrm{HCl}\right)$.
• Chlorine burns in hydrogen to give Hydrogen chloride gas.
  $$\begin{gathered} {\mathrm{H}}_2\left(\mathrm{g}\right)+{\mathrm{Cl}}_2\left(\mathrm{g}\right)\stackrel{\mathrm{diffused}\mathrm{sunlight}}{\to }2\mathrm{HCl}\left(\mathrm{g}\right) \\ \mathrm{Hydrogen} \\ \mathrm{chloride} \end{gathered}$$
• Hydrogen chloride gas on reaction with Ammonia, gives dense fumes of Ammonium chloride $\left({\mathrm{NH}}_4\mathrm{Cl}\right)$
  $$\begin{gathered} {\mathrm{NH}}_3\left(\mathrm{g}\right)+\mathrm{HCl}\left(\mathrm{g}\right)\to {\mathrm{NH}}_4\mathrm{Cl}\left(\mathrm{g}\right) \\ \mathrm{Ammonia}\mathrm{Ammonium} \\ \mathrm{chloride} \end{gathered}$$