$A$ 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 = $1.0 \, kcal/kg \cdot K$)

In a constant pressure process for $5 \text{ mole}$ of an ideal monoatomic gas,the temperature of the gas increased from $300 \ K$ to $500 \ K$. Which of the following is incorrect regarding the process?

For the reaction $2X_{(s)} + 2Y_{(s)} \to 2C_{(\ell)} + D_{(g)}$,the value of $q_p$ is $-28 \, \text{kcal mol}^{-1}$ at $2700 \, ^\circ\text{C}$. Calculate the value of $q_v$ in $\text{kcal mol}^{-1}$.

An ideal gas in a thermally insulated vessel at internal pressure $= P_1$,volume $= V_1$ and absolute temperature $= T_1$ expands irreversibly against zero external pressure,as shown in the diagram. The final internal pressure,volume and absolute temperature of the gas are $P_2, V_2$ and $T_2$,respectively. For this expansion,
$(A) \ q = 0$
$(B) \ T_2 = T_1$
$(C) \ P_2 V_2 = P_1 V_1$
$(D) \ P_2 V_2^\gamma = P_1 V_1^\gamma$

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

The molar heat of neutralization of $NaOH$ with $HCl$ in comparison to that of $KOH$ with $HNO_3$ is: