For the reaction at $25^{\circ} C$, $X_2O_{4(l)} \longrightarrow 2 XO_{2(g)}$, $\Delta U$ and $\Delta S$ are $2.1 \ kCal$ and $20 \ cal \ K^{-1}$ respectively. What is $\Delta G$ for the reaction at the same temperature? $(R = 2 \ cal \ K^{-1} \ mol^{-1})$

$200 \ mL$ of $0.2 \ M \ HCl$ is mixed with $300 \ mL$ of $0.1 \ M \ NaOH$. The molar heat of neutralization of this reaction is $-57.1 \ kJ \ mol^{-1}$. The increase in temperature in $^{\circ}C$ of the system on mixing is $x \times 10^{-2}$. The value of $x$ is ....... . (Nearest integer)
[Given : Specific heat of water $= 4.18 \ J \ g^{-1} \ K^{-1}$
Density of water $= 1.00 \ g \ cm^{-3}$]
(Assume no volume change on mixing)

Standard enthalpy of vapourisation for $CCl_4$ is $30.5 \ kJ \ mol^{-1}$. Heat required for vapourisation of $284 \ g$ of $CCl_4$ at constant temperature is . . . . . . $kJ$. (Given molar mass in $g \ mol^{-1} ; C=12, Cl=35.5$ )

For the gas phase reaction,$PCl_{5(g)} \rightleftharpoons PCl_{3(g)} + Cl_{2(g)}$,which of the following conditions are correct?

For the reaction $H_{2}O_{(l)} \rightleftharpoons H_{2}O_{(g)}$ at $373 \ K$ and $1 \ atm$ pressure:

For the reaction $CO_{(g)} + \frac{1}{2}O_{2_{(g)}} \rightarrow CO_{2_{(g)}}$ at $17^o C$ and constant volume,the heat of reaction is $-67.71 \, K \, cal$. What is the heat of reaction at constant pressure at $17^o C$ in $K \, cal$?