Question

In simple english why is constant temperature so important in Boyle's law?
And also does Boyle's law still hold true at a constant very high temperature or pressure?

Answer 1

As per equation of state, we have

PV = nRT

and we know that boyle's law is a relation between Pressure and volume. In order to verift this relationship, everything on the right hand side should be constant. As n and R are constant for a gas, Temperature must be held constant in order for the boyle's law to work.

For most of the temperature tanges, boyle's law works pretty well. However, if we really go in deep then we will know that at very low temperatures there will come a point at which the gas will condense into a liquid. Suddenly Boyle’s Law stops applying. At very high temperatures the gas will become a plasma, and again Boyle’s Law will stop applying. However, for all pracrtical temperature range, we use today, this law holds true.