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Chemistry · THERMODYNAMICS
हिन्दीDuring an irreversible expansion of an ideal gas from an initial volume of \( 3.0\text{ L} \) to a final volume of \( 8.0\text{ L} \) against a constant external pressure of \( 2.5\text{ bar} \), the gas absorbs \( 750\text{ J} \) of heat. Given \( 1\text{ L}\cdot\text{bar} = 100\text{ J} \), the change in internal energy (\( \Delta U \)) of the gas is:
Correct answer · Option 2
\( -500\text{ J} \)
Explanation
\( w = -p_{\text{ex}}\Delta V = -2.5\text{ bar} \times (8.0 - 3.0)\text{ L} = -12.5\text{ L}\cdot\text{bar} = -1250\text{ J} \). From the First Law, \( \Delta U = q + w = 750\text{ J} + (-1250\text{ J}) = -500\text{ J} \).
