We are going to consider that is a ideal gas and then it accomplish the following equation:
P*V = n*R*T
where P is pressure, V is volume, n is mols, T is temperature and R is a constant value of 0.082 (atm*l)/(mol*K)
First we need to change the units of pressure 300.12 kpa = 2.96 atm
Then:
V = 0.2 * 0.082 * 229 / 2.96 = 1.27 liters
So the volume of the jar is 1.27 liters