Two students set up tubes as shown. cotton wool soaked in concentrated hydrochloric acid tube 1 blue litmus paper tube 2 cotton wool soaked in concentrated hydrobromic acid blue litmus paper Concentrated hydrochloric acid produces fumes of hydrogen chloride. Concentrated hydrobromic acid produces fumes of hydrogen bromide. Four minutes after setting up the experiment, the litmus paper in tube 1 turns red. Seven minutes after setting up the experiment, the litmus paper in tube 2 turns red. Use the kinetic particle theory to explain how the gases move through the tubes,

1. (a)(i)Two students set up tubes as shown. cotton wool soaked in concentrated hydrochloric acid tube 1 blue litmus paper tube 2 cotton wool soaked in concentrated hydrobromic acid blue litmus paper Concentrated hydrochloric acid produces fumes of hydrogen chloride. Concentrated hydrobromic acid produces fumes of hydrogen bromide. Four minutes after setting up the experiment, the litmus paper in tube 1 turns red. Seven minutes after setting up the experiment, the litmus paper in tube 2 turns red. Use the kinetic particle theory to explain how the gases move through the tubes,[2]
2. (a)(ii)why the gases take different times to reach the litmus paper.[1]
3. (b)A gas syringe is filled with 80 cm³ of hydrogen chloride gas at 20°C. The syringe is placed in some hot water at 50 °C. The atmospheric pressure does not change but the volume of the gas in the syringe increases to 88 cm³. hot water hydrogen chloride blocked syringe end 80 cm³ 20 °C 88 cm³ hydrogen chloride 50°C Use the kinetic particle theory to explain why the volume increases.[2]

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