The enthalpies of combustion of carbon and carbon monoxide are $-393.5 \, kJ/mol$ and $-283 \, kJ/mol$ respectively. The enthalpy of formation of carbon monoxide in $kJ/mol$ is: (in $.5$)

The enthalpy of neutralization is about $57.3 \ kJ$ for the pair:

Given: $2Zn + O_2 \rightarrow 2ZnO, \Delta G^o = -616 \, J$; $2Zn + S_2 \rightarrow 2ZnS, \Delta G^o = -293 \, J$; $S_2 + 2O_2 \rightarrow 2SO_2, \Delta G^o = -408 \, J$. The value of $\Delta G^o$ for the reaction $2ZnS + 3O_2 \rightarrow 2ZnO + 2SO_2$ is ....... $J$.

Calculate the heat required to convert $9 \ g$ of liquid water to water vapor using the following equations:
$H_{2(g)} + 1/2 O_{2(g)} \longrightarrow H_2O_{(g)} \quad \Delta H = -57 \ kCal$
$H_{2(g)} + 1/2 O_{2(g)} \longrightarrow H_2O_{(l)} \quad \Delta H = -68.3 \ kCal$ (in $kCal$)

Comment on the thermodynamic stability of $NO_{(g)}$,given:
$\frac{1}{2} N_{2(g)} + \frac{1}{2} O_{2(g)} \rightarrow NO_{(g)}; \Delta_r H^{\ominus} = 90 \, kJ \, mol^{-1}$
$NO_{(g)} + \frac{1}{2} O_{2(g)} \rightarrow NO_{2(g)}; \Delta_r H^{\ominus} = -74 \, kJ \, mol^{-1}$

The enthalpy change $(\Delta H)$ for the process $N_2H_{4(g)} \to 2N_{(g)} + 4H_{(g)}$ is $1724 \ kJ \ mol^{-1}$. If the bond energy of $N-H$ bond in ammonia is $391 \ kJ \ mol^{-1}$,what is the bond energy of $N-N$ bond in $N_2H_4$ in $kJ \ mol^{-1}$?