Which of the following equations represents the standard enthalpy of formation of $CH_4$?

For the reaction,$H_{2(g)} + I_{2(g)} \to 2HI_{(g)}$,$\Delta H = -12.40 \ kcal$. According to this,the heat of formation of $HI$ will be......$kcal$.

Given that,$C_{(s)} + O_{2(g)} \longrightarrow CO_{2(g)} ; \Delta H^{\circ} = -x \ kJ \ mol^{-1}$ and $2CO_{(g)} + O_{2(g)} \longrightarrow 2CO_{2(g)} ; \Delta H^{\circ} = -y \ kJ \ mol^{-1}$. The enthalpy of formation of $CO$ will be:

Given: $H_2 + 1/2 O_2 \rightarrow H_2O : \Delta H = -68.4 \ \text{kcal}$,$C + O_2 \rightarrow CO_2 : \Delta H = -94.0 \ \text{kcal}$,and $C_2H_5OH + 3O_2 \rightarrow 2CO_2 + 3H_2O : \Delta H = -327.0 \ \text{kcal}$. Calculate the heat of formation of $C_2H_5OH$ in $\text{kcal}$.

Given that $:$
$2 C_{(s)} + 2 O_{2_{(g)}} \rightarrow 2 CO_{2_{(g)}} ; \Delta H = -787 \ kJ$
$H_{2_{(g)}} + \frac{1}{2} O_{2_{(g)}} \rightarrow H_2 O_{(l)} ; \Delta H = -286 \ kJ$
$C_2 H_{2_{(g)}} + \frac{5}{2} O_{2_{(g)}} \rightarrow 2 CO_{2_{(g)}} + H_2 O_{(l)} ; \Delta H = -1301 \ kJ$
The heat of formation of acetylene will be $:-$

Calculate the heat of combustion (in $kJ$) of methane from the following data:
$(i)$ $C_{\text{(graphite)}} + 2H_{2(g)} \rightarrow CH_{4(g)} \quad \Delta H = -74.8 \ kJ$
(ii) $C_{\text{(graphite)}} + O_{2(g)} \rightarrow CO_{2(g)} \quad \Delta H = -393.5 \ kJ$
(iii) $H_{2(g)} + 1/2 O_{2(g)} \rightarrow H_2O_{(l)} \quad \Delta H = -286.2 \ kJ$