The enthalpy of formation of $H_2O$ is $-68 \ k.cal/mol$. Calculate the enthalpy of formation of $OH^-$. Given that the enthalpy of neutralization of $H^+$ and $OH^-$ is $-13.7 \ k.cal/mol$.

$A$ gas at $10 \, atm$ pressure and $300 \, K$ temperature undergoes adiabatic reversible expansion to $5 \, atm$ pressure and $290 \, K$ temperature. The molar heat capacity $C_v$ of the gas in $cal \, mol^{-1} \, K^{-1}$ is:

Match the conditions and the temperature for the 'fusion' process of $H_2O_{(s)}$ at $1 \ atm$ pressure.

Condition	Temperature
$(1)$. Spontaneous	$(p)$. $273 \ K$
$(2)$. At equilibrium	$(q)$. $260 \ K$
$(3)$. Non-spontaneous	$(r)$. $280 \ K$

For the reaction $2 Cl ( g ) \rightarrow Cl _{2}( g )$,the correct option is

For a hypothetical reaction $A_{2(g)} + B_{2(g)} \rightleftharpoons 2AB_{(g)}$,at $200 \ K$,$\Delta_r G$ and $\Delta_r S$ are $20 \ kJ \ mol^{-1}$ and $-20 \ J \ K^{-1} \ mol^{-1}$ respectively. If $\Delta_r C_p = 20 \ J \ K^{-1} \ mol^{-1}$,find $\Delta_r H$ at $400 \ K$ in $kJ \ mol^{-1}$.

When $2.0 \ g$ of sucrose is oxidized to form $CO_{2(g)}$ and $H_2O(\ell)$,the internal energy changes by $-24 \ kJ$. Calculate the value of $\Delta H$ at $298 \ K$ in $kJ \ mol^{-1}$. (Molar mass of sucrose $= 342 \ g \ mol^{-1}$)