The enthalpy change for a reaction does not depend on:

Calculate the enthalpy of formation of ethylene $(C_2H_4)$ from the following data:
$(I)$ $C_{\text{(graphite)}} + O_{2(g)} \longrightarrow CO_{2(g)}$; $\Delta H = -393.5 \ kJ$
$(II)$ $H_{2(g)} + \frac{1}{2} O_{2(g)} \longrightarrow H_2O_{(l)}$; $\Delta U = -256.2 \ kJ$
$(III)$ $C_2H_{4(g)} + 3 O_{2(g)} \longrightarrow 2 CO_{2(g)} + 2 H_2O_{(l)}$; $\Delta H = -1410.8 \ kJ$ (in $kJ$)

Given: $S + \frac{3}{2} O_2 \to SO_3 + 2x \ \text{kcal}$,$\Delta H = -2x \ \text{kcal}$ and $SO_2 + \frac{1}{2} O_2 \to SO_3 + y \ \text{kcal}$,$\Delta H = -y \ \text{kcal}$. Find the heat of formation of $SO_2$.

The standard enthalpies of combustion of $C_6H_{6(l)}$,$C(graphite)$ and $H_{2(g)}$ are respectively $-3270 \ kJ \ mol^{-1}$,$-394 \ kJ \ mol^{-1}$ and $-286 \ kJ \ mol^{-1}$. What is the standard enthalpy of formation of $C_6H_{6(l)}$ in $kJ \ mol^{-1}$?

The bond dissociation enthalpies of $H_2$,$Cl_2$,and $HCl$ are $434$,$242$,and $431 \ kJ \ mol^{-1}$ respectively. What is the enthalpy of formation of $HCl$ in $kJ \ mol^{-1}$?

Equal volumes of methanoic acid and sodium hydroxide are mixed. If $x$ is the heat of formation of water,then the heat evolved on neutralization is