The enthalpies of formation of $N_2O$ and $NO$ are $28$ and $90 \ kJ \ mol^{-1}$ respectively. The enthalpy of the reaction,$2N_2O_{(g)} + O_{2(g)} \to 4NO_{(g)}$ is equal to.....$kJ$

Given:
$C + 2S \to CS_2 ; \Delta H_f^o = +117.0 \, kJ \, mol^{-1} \dots (1)$
$C + O_2 \to CO_2 ; \Delta H_f^o = -393 \, kJ \, mol^{-1} \dots (2)$
$S + O_2 \to SO_2 ; \Delta H_f^o = -297 \, kJ \, mol^{-1} \dots (3)$
The heat of reaction for $CS_2 + 3O_2 \to CO_2 + 2SO_2$ is:
.....$kJ \, mol^{-1}$

If at $298 \, K$ the bond energies of $C-H, C-C, C=C$ and $H-H$ bonds are respectively $414, 347, 615$ and $435 \, kJ \, mol^{-1}$,the value of enthalpy change for the reaction $H_2C=CH_{2(g)} + H_{2(g)} \to H_3C-CH_{3(g)}$ at $298 \, K$ will be $.... \, kJ$.

The standard enthalpy of formation of liquid water at $25^{\circ} C$ is approximately:
$H_{2(g)} + \frac{1}{2} O_{2(g)} \longrightarrow H_2O_{(l)}$

The value of the enthalpy of neutralization of an acid and a base is significant only when $......$

In the reaction for the transition of carbon in the diamond form to carbon in the graphite form,$\Delta H = -453.5 \ cal$. This points out that