Question

Figure 11 shows a setup that can be used to verify Charles' Law.

1. Explain how the:
   • temperature of air in the tube is measured;
   • volume of air in the tube is measured. 
2. State how the pressure is kept constant during the experiment.
3. State how the measurements in (1) can be used to verify Charles' law. 
4. State one precaution that must be taken to ensure that the temperature of air is accurately measured.

Answer 1

1.     
   • By measuring the temperature of water since the temperature of air is equal to that of water.
   • By measuring length of air column. Volume of air is proportional to the lenght since the cross-sectional area is uniform
2. Keeping the tube(vertical) and open throughout the experiment.
3.  
   • Obtain several values of volume V and Temperature T/ calculate several ratios of V
   • Plot a graph of volume against absolute temperature
   • A straight line through origin is obtained showing Charles' law is obeyed.
4. Stirring water before taking and recording temperature and volume