The final temperature : 313.06 °C
Gay Lussac's Law
When the volume is not changed, the gas pressure is proportional to its absolute temperature
[tex]\dfrac{P_1}{T_1}=\dfrac{P_2}{T_2}[/tex]
P1=0.3 atm
T1=25 + 273=298 K
P2=0.59 atm
[tex]\tt \dfrac{0.3}{298}=\dfrac{0.59}{T_2}\\\\T_2=586.06=313.06~^oC[/tex]