An engine operating between $150\,^{\circ}C$ and $25\,^{\circ}C$ takes $500\,J$ of heat from a higher temperature reservoir. If there are no frictional losses,the work done by the engine is.....$J$.

Which of the following statements is incorrect when a system consisting of an ideal gas undergoes a change of state?

The entropy of a sample of a certain substance increases by $0.836 \ J \ K^{-1}$ on adding reversibly $0.3344 \ J$ of heat at constant temperature. The temperature of the sample is.....$K$

Standard entropy of $X_2, Y_2$ and $XY_3$ are $60, 40$ and $50 \ J \ K^{-1} \ mol^{-1},$ respectively. For the reaction,$\frac{1}{2}X_2 + \frac{3}{2}Y_2 \to XY_3, \ \Delta H = -30 \ kJ,$ to be at equilibrium,the temperature will be ............... $K$.

The enthalpy change for the conversion of water into vapor at $27^\circ C$ is $30 \ kJ/mol$. The entropy change for this process in $J/mol \ K$ is:

One mole of water at $100\,^{\circ}C$ is converted into steam at $100\,^{\circ}C$ at a constant pressure of $1\,atm$. The change in entropy is [heat of vaporisation of water at $100\,^{\circ}C = 540\,cal/g$].