Answer:
313 K or 40 degree celsius.
Explanation:
Initial , [tex]V_{i}=V_{0}[/tex]
[tex]P_{i}=P_{0}[/tex]
[tex]T_{i} =40+273=313K[/tex]
Now, final
[tex]P_{f} =\frac{1}{2}P_{0}[/tex]
[tex]V_{f} =2V_{0}[/tex]
Combined the ideal gas law
[tex]\frac{P_{i}V_{i}}{T_{i}}=\frac{P_{f}V_{f}}{T_{f}} \\\frac{P_{0}V_{0}}{T_{0}}=\frac{1}{2} \frac{P_{0}2V_{0}}{T_{f}} \\T_{f}=T_{0}\\T_{f}=313K[/tex]
Therefore, the final temperature of ideal gas is 313 K.