a chemist delivers 1.5 moles of oxygen gas to a 2.0 L evacuated cylinder containing excess sulfur. He then ignites the mixture and the following...

a chemist delivers 1.5 moles of oxygen gas to a 2.0 L evacuated cylinder containing excess sulfur. He then ignites the mixture and the following combustion reaction goes to completion:

2 S(s) +3 O2 (g) ---> 2 SO3 (g).

When reaction is complete the temperature of the cylinder is 500 K. What is the pressure under the cylinder.