A sample of oxygen has a pressure of 500. kPa at 40.0∘C. What will be the temperature in Kelvin at a pressure of 630. kPa?

Initial : P₁ = 500 kPa, T₁ = (273.2 + 40.0) K = 313.2 K
Final : P₂ = 630 kPa, T₂ = ? K

For a fixed amount of gas with constant volume, P₁/T₁ = P₂/T₂
Final temperature, T₂ = T₁ × (P₂/P₁) = 313.2 × (630/500) = 395 K

(40+273)*630/500=394.38=121.38 deg. C