<|system|>
Calculate $\Delta G$ for the isothermal expansion of $2.25 \mathrm{~mol}$ of an ideal gas at $325 \mathrm{~K}$ from an initial pressure of 12.0 bar to a final pressure of 2.5 bar.</s>.
<|user|>
Can you answer based on context?
<|assistant|>
-9.54