When an ideal gas in a cylinder was compressed isothermally by a piston,the work done on the gas was found to be $1.5 \times 10^4 \ J$. During this process,about:

During which thermodynamic process does $T$ remain constant, while the other two variables $P$ and $V$ change?

Two identical vessels $A$ and $B$ with frictionless pistons contain the same ideal gas at the same temperature and the same volume $V$. The masses of gas in $A$ and $B$ are $m_A$ and $m_B$, respectively. The gases are allowed to expand isothermally to the same final volume $2V$. The changes in pressures of the gas in $A$ and $B$ are found to be $\Delta P$ and $1.5 \Delta P$, respectively. Then

One mole of an ideal gas expands from an initial volume of $10 \; L$ to a final volume of $20 \; L$ at a constant temperature of $300 \; K$. Calculate the work done by the gas in $J$. $(R = 8.31 \; J/mol \cdot K)$ (in $; J$)

Two identical containers $A$ and $B$ with frictionless pistons contain the same ideal gas at the same temperature and the same volume $V$. The mass of the gas in $A$ is ${m_A}$ and that in $B$ is ${m_B}$. The gas in each cylinder is now allowed to expand isothermally to the same final volume $2V$. The changes in the pressure in $A$ and $B$ are found to be $\Delta P$ and $1.5 \Delta P$ respectively. Then:

The temperature of an ideal gas is kept constant as it expands. The gas does external work. During this process,the internal energy of the gas