A 0.50 mol sample of oxygen gas is confined a 0° C in a cylinder. The initial pressure in the cylinder is 1.0 atm. If the gas is compressed by a piston so that the final volume is 62.3% of the initial volume and the final pressure of the gas is 2.15 atm. What is the final temperature of the gas in kelvin? Enter your answer to the nearest degree.

The answer is 366 K

What am I doing wrong here? Here is my game plan

Using V= Nrt/p to find the initial volume

0.50x0.08206x273/1.00 = 11.20l

11.20 x 0.623= 6.9776

11.20 -6.9776 = 4.2224L ------ final volume

Now solve for Final T

pv/nr = T

2.15atm X 4.2224L / 1.00 * 0.08206 = 110.62

I have an exam tommorrow so explanation on this problem will be greatly appreciated.