The $\Delta H^o_f$ for $CO_{2(g)}$,$CO_{(g)}$,and $H_2O_{(g)}$ are $-393.5$,$-110.5$,and $-241.8 \ kJ/mol$ respectively. The standard enthalpy change (in $kJ$) for the reaction $CO_{2(g)} + H_{2(g)} \to CO_{(g)} + H_2O_{(g)}$ is:

Hess's law of constant heat summation includes:

When equal volumes of $1 \ M \ HCl$ and $1 \ M \ H_2SO_4$ are separately neutralized by an excess volume of $1 \ M \ NaOH$ solution,$x \ J$ and $y \ J$ of heat are liberated,respectively. The value of $y / x$ is . . . .

Calculate $\Delta_r H$ $(kJ \ mol^{-1})$ of the following reaction:
$C_2H_5OH_{(l)} + \frac{7}{2}O_{2(g)} \rightarrow 2CO_{2(g)} + 3H_2O_{(l)}$

Molecule	$\Delta_f H^0 (kJ \ mol^{-1})$
$C_2H_5OH_{(l)}$	$-280$
$CO_{2(g)}$	$-400$
$H_2O_{(l)}$	$-290$

Consider the following reaction:
$C_{(s)} + O_{2(g)} \to CO_{2(g)} + x \ kJ$
$CO_{(g)} + \frac{1}{2}O_{2(g)} \to CO_{2(g)} + y \ kJ$
The heat of formation of $CO_{(g)}$ is:

Calculate the $N-N$ bond energy in $N_2H_4$ from the given bond enthalpy data.
$\varepsilon_{N-H} = 393 \ kJ/mol$
$\varepsilon_{H-H} = 436 \ kJ/mol$
$\Delta H_{vap}[N_2H_{4(l)}] = 18 \ kJ/mol$
$N_2H_{4(l)} + H_{2(g)} \to 2NH_{3(g)} : \Delta H = -142 \ kJ/mol$
....... $kJ/mol$