Temperature - Pressure

1. The problem statement, all variables and given/known data

A cylinder of nitrogen is pressurised to 200 BAR at 25oC
The cylinder is left to cool outside on a winters day to –5oC

What is the pressure of the Nitrogen once it has cooled?



2. Relevant equations

P1/T1=P2/T2 ?


3. The attempt at a solution

25+273 = 298 Kelvin. 273-5=268 Kelvin.

200/298=0.6711409396

0.6711409396 x 268 = 179 BAR ?

Have i used the relevant equation? Going through some practice questions but cant find the solutions. doh.

cheers