For irreversible expansion of an ideal gas under isothermal condition,the correct option is :

$A$ steel steam boiler has a mass of $900 \, kg$ and contains $400 \, kg$ of water. If the boiler and water receive only $70 \%$ of the heat supplied,how much heat in $kcal$ is required to raise the temperature of the boiler and water from $10 \, ^oC$ to $100 \, ^oC$? (Specific heat of steel = $0.11 \, kcal/kg \cdot K$,Specific heat of water = $1.0 \, kcal/kg \cdot K$)

If standard molar enthalpy change and standard molar internal energy change measured in a bomb calorimeter are equal,which one of the following statements is correct?

Consider the $P-V$ (pressure-volume) diagram given below,where an ideal gas is reversibly converted from state $X$ to state $Y$. Among the following,which is the correct $T-S$ (temperature-entropy) diagram corresponding to this process?

The molar heat capacity for an ideal gas at constant pressure is $20.785 \ J \ K^{-1} \ mol^{-1}$. The change in internal energy is $5000 \ J$ upon heating it from $300 \ K$ to $500 \ K$. The number of moles of the gas is [Nearest integer] (Given: $R = 8.314 \ J \ K^{-1} \ mol^{-1}$)

The heat evolved in the combustion of methane is given by the following equation: $CH_{4(g)} + 2O_{2(g)} \to CO_{2(g)} + 2H_2O_{(l)}$; $\Delta H = -890.3 \ kJ$. How many grams of methane would be required to produce $445.15 \ kJ$ of heat of combustion?