Answer :
In the first condition: P1 = 2.0 atm V1 = 15.0 L P1V1 = Ki 2 * 15 = Ki Ki = 30
In the second condition Pt = 4.0 atm Vt = 7.5L Pt * Vt = Kt 4.0 * 7.5 = Kt Kt = 30
Conclusion: Ki = Kt. Since the two values of k are the same. Therefore, the gas obeys Boyle's Law. Take note Boyle’s law is an ideal gas law which tells us that the volume of an ideal gas is contrariwise proportional to its absolute or total pressure at a constant temperature.