Two students arranged the tubes as shown. Cotton wool dipped in concentrated hydrochloric acid gives off hydrogen chloride fumes. Cotton wool dipped in concentrated hydrobromic acid gives off hydrogen bromide fumes.
(a(i))[2]
Use the kinetic particle theory to explain how the gases pass through the tubes.
(a(ii))[1]
Use the kinetic particle theory to explain why the gases need different lengths of time to reach the litmus paper.
(b)[2]
Use the kinetic particle theory to explain why the volume of hydrogen chloride gas increases when it is heated from $20^\circ\text{C}$ to $50^\circ\text{C}$ while the pressure stays constant.
Worked solution & mark scheme
This 5-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Diffusion” …