During an isothermal expansion, a confined ideal gas does $150 \mathrm{~J}$ of work against its surroundings…
During an isothermal expansion, a confined ideal gas does $150 \mathrm{~J}$ of work against its surroundings. This implies that
$300 \mathrm{~J}$ of heat has been added to the gas
no heat is transferred because the process is is othermal
$150 \mathrm{~J}$ of heat has been added to the gas
$150 \mathrm{~J}$ of heat has been removed from the gas
Solution
By first law of thermodynamics -
$\begin{aligned}
\mathrm{dQ} & =\mathrm{dV}+\mathrm{dW} \\
\mathrm{dV} & =0 \text { for isothermal process } \\
\mathrm{dQ} & =\mathrm{dW} \\
& =+150
\end{aligned}$
$\Rightarrow 150 \mathrm{~J}$ of heat has been added to the system.
So, the correct answer is ' $150 \mathrm{~J}$ of heat has been added to the gas'.
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