10. Figure 15 shows a balloon filled with helium gas.
i- Which statements describe the movement of the gas particles in the balloon?
[2 marks]
ANSWER
ii- The pressure of the helium in the balloon is 100 000 Pa.
The volume of the balloon is 0.030 m3.
The balloon is compressed at a constant temperature causing the volume to decrease
to 0.025 m3.
No helium leaves the balloon.
Calculate the new pressure in the balloon.
[4 marks]
SOLUTION
iii- The temperature of the helium in the balloon was increased.
The mass and volume of helium in the balloon remained constant.
Explain why the pressure exerted by the helium inside the balloon would increase.
[4 marks]
ANSWER
As the temperature of the helium in the balloon is increased, particles gain kinetic energy. This causes more collisions per second of the helium particles with the wall of balloon. Therefore, greater force acts on the walls which means that there is greater force acting per unit area. Hence, pressure exerted by the helium inside the balloon would increase.
