(a)[4]
After a short time, solid ammonium bromide was seen on the tube walls at point X. Use the kinetic particle theory to explain this result.
(b)[1]
A gas syringe contains $70\,\text{cm}^3$ of ammonia gas. The pressure on the plunger is raised. The temperature stays the same but the volume in the syringe drops to $60\,\text{cm}^3$. Use the kinetic particle theory to explain why the volume decreases.