Question

consider these equations.
ch₄(g) → c(s) + 2h₂(g) δh₁ = 74.6kj
c(s) + 2cl₂(g) → ccl₄(g) δh₂ = - 95.7kj
2h₂(g) + 2cl₂(g) → 4hcl(g) δh₃ = -184.6kj
ch₄(g) + 4cl₂(g) → ccl₄(g) + 4hcl(g) δh₄ = -205.7kj
complete this based on the diagram.
arrow d:
represents an intermediate reaction
has a magnitude that is always higher than any intermediate reaction
represents the overall enthalpy of reaction

Explanation:

Step1: Analyze reaction - enthalpy relationship

The overall reaction is $CH_4(g)+4Cl_2(g)
ightarrow CCl_4(g) + 4HCl(g)$ with $\Delta H_4=- 205.7kJ$. The arrow D in the diagram represents the overall change from the initial state to the final state. In thermochemistry, the overall enthalpy change of a reaction is the difference in enthalpy between the reactants and the products. The overall enthalpy change is not an intermediate - reaction enthalpy. And there is no information to suggest its magnitude is always higher than any intermediate reaction.

Answer:

represents the overall enthalpy of reaction