Pressure is defined as force per unit area.
Another way to look at it is that PV remains constant, and if either of the two is allowed to vary, the other changes so that the value for PV remains unchanged. This concept makes sense when considered practically. With the clip open, set the syringe to a volume of .0100 m 3 . Seal the straw by closing the clip. Record this information in Data Table 1 as Trial 1 with Mass 0.