Chemistry

This problem tests your understanding of isothermal expansion and the first law of thermodynamics. The key insight is that for an ideal gas, internal energy $\Delta U$ depends only on temperature—since temperature is constant here, $\Delta U = 0$ immediately. From there, the first law ($\Delta U = q + W$) tells you that $q$ and $W$ must be equal and opposite. Calculate work using $W = -P_{\text{ext}} \Delta V$ (where $\Delta V$ comes from the ideal gas law), then use energy conservation to find heat.

This problem tests your understanding of isothermal expansion and the first law of thermodynamics. The key insight is that for an ideal gas, internal energy $\Delta U$ depends only on temperature—since temperature is constant here, $\Delta U = 0$ immediately. From there, the first law ($\Delta U = q + W$) tells you that $q$ and $W$ must be equal and opposite. Calculate work using $W = -P_{\text{ext}} \Delta V$ (where $\Delta V$ comes from the ideal gas law), then use energy conservation to find heat.