The heat of neutralisation of a strong acid and a strong alkali is $57.0 \ kJ \ mol^{-1}$. The heat released when $0.5 \ mol$ of $HNO_3$ solution is mixed with $0.2 \ mol$ of $KOH$ is: (in $kJ$)

Enthalpy of formation of $CO_{(g)}$,$CO_{2(g)}$,$N_2O_{(g)}$ and $N_2O_{4(g)}$ are $-110$,$-393$,$81$,and $9.7 \ kJ \ mol^{-1}$ respectively. Calculate $\Delta_r H$ for the following reaction: $N_2O_{4(g)} + 3 CO_{(g)} \longrightarrow N_2O_{(g)} + 3 CO_{2(g)}$

When equal volumes of molar hydrochloric acid $(HCl)$ and sulfuric acid $(H_2SO_4)$ are neutralized by a dilute $NaOH$ solution,the heat produced is $x \ KCal$ and $y \ KCal$ respectively. Which of the following is correct?

The enthalpy of formation of ethane $(C_2H_6)$ from ethylene $(C_2H_4)$ by the addition of hydrogen,where the bond energies of $C-H$,$C-C$,$C=C$,and $H-H$ are $414 \ kJ/mol$,$347 \ kJ/mol$,$615 \ kJ/mol$,and $435 \ kJ/mol$ respectively,is $........$ $kJ/mol$.

The enthalpies of combustion of diamond and graphite are $-395.4 \, kJ$ and $-393.5 \, kJ$ respectively. The enthalpy of transformation of diamond to graphite is ..... $kJ$.

In the reaction: $H_2 + Cl_2 \to 2HCl, \Delta H = -194 \ kJ$. The heat of formation of $HCl$ is ........ $kJ$.