720.535 K
Concept tested: Combined gas law
From the question we are given;
We are required to calculate the new temperature, T2of the gas;
[tex]\frac{P1V1}{T1}=\frac{P2V2}{T2}[/tex]
[tex]T2=\frac{P2V2T1}{P1V1}[/tex]
[tex]T2=\frac{(2.50atm)(435mL)(355K)}{(1.88atm)(285mL)}[/tex]
[tex]T2=720.535K[/tex]
Therefore, the new temperature of the gas in the syringe must be 720.535 K