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: $N_2O_{4(g)} + 3 CO_{(g)} \longrightarrow N_2O_{(g)} + 3 CO_{2(g)}$

$C + \frac{1}{2} O_2 \to CO; \Delta H = -42 \ kJ$
$CO + \frac{1}{2} O_2 \to CO_2; \Delta H = -24 \ kJ$
The heat of formation of $CO_2$ is ..... $kJ$.

The oxidizing power of chlorine in an aqueous solution can be determined by the parameters given below. What is the total energy change in $kJ \ mol^{-1}$ for the conversion of $\frac{1}{2} Cl_{2(g)}$ to $Cl^-_{(aq)}$?
$\frac{1}{2} Cl_{2(g)}$ $\xrightarrow{\frac{1}{2} \Delta_{diss} H^\Theta} Cl_{(g)}$ $\xrightarrow{\Delta_{eg} H^\Theta} Cl^-_{(g)}$ $\xrightarrow{\Delta_{hyd} H^\Theta} Cl^-_{(aq)}$
(Given: $\Delta_{diss} H_{Cl_2}^\Theta = 240 \ kJ \ mol^{-1}$,$\Delta_{eg} H_{Cl}^\Theta = -349 \ kJ \ mol^{-1}$,$\Delta_{hyd} H_{Cl^-}^\Theta = -381 \ kJ \ mol^{-1}$)

The heat of neutralization of a strong acid and a weak base is:

The standard enthalpy of formation of carbon monoxide at $298 \ K$ is $-110.5 \ kJ/mol$. The standard internal energy of formation of carbon monoxide at $298 \ K$ and constant volume is ............... $kJ/mol$. (in $.73$)

$C + 2S \rightarrow CS_2$; $\Delta H^o = +117 \, kJ \, mol^{-1}$; $C + O_2 \rightarrow CO_2$; $\Delta H^o = -393 \, kJ \, mol^{-1}$; $S + O_2 \rightarrow SO_2$; $\Delta H^o = -297 \, kJ \, mol^{-1}$. The heat of combustion of $CS_2$ in $kJ \, mol^{-1}$ is: