Givens.
• Volume = 1.5 mL.
,• Moles = 0.25 moles.
,• Temperature = 225 Celsius.
First, transform the volume into L.
[tex]1.5mL\cdot\frac{1L}{1000mL}=0.0015L[/tex]Then, use the ideal gas law and solve for P.
[tex]\begin{gathered} PV=\text{nRT} \\ P=\frac{\text{nRT}}{V}=\frac{0.25\text{mol}\cdot0.08206\cdot\frac{L\cdot\text{atm}}{mol\cdot K}\cdot498.15K}{0.0015L} \\ P=6813.03atm \end{gathered}[/tex]Therefore, the pressure is 6813.03 atm.