J.R. S. answered • 02/20/19

Ph.D. University Professor with 10+ years Tutoring Experience

Combined gas law at constant volume = Gay-Lussac's law

P1/T1 = P2/T2

P1 = 2.5 atm

T1 = -13 + 273 = 260K

P2 = 1.2 atm

T2 = ?

Solve for T2 and don't forget to subtract 273 to convert back to degrees celsius.