Please solve this and explain it.

Dear student


 $$\begin{gathered} The reactions are \\ 2C \left(s\right) + 4H_2 \left(g\right)\stackrel{∆H1}{\to }2C\left(g\right) +4H_2\left(g\right) \\ 2C\left(g\right) +4H_2\left(g\right)\stackrel{∆H2}{\to }2C\left(g\right) +8H\left(g\right) \\ 2C \left(s\right) + 4H_2 \left(g\right)\stackrel{∆H3}{\to 2}CH4\left(g\right) \\ 2C\left(g\right) +8H\left(g\right)\stackrel{∆H4}{\to }2CH4\left(g\right) \end{gathered}$$

i)The heat of formation is $∆H_3 + ∆H_4$
ii)heat of sublimation is ΔH₁
iii)heat of sissociation is  ΔH<sub>2

Regards</sub>