Calculate the `Delat_(r )H^(Θ)` for the reaction
`H-underset(Cl)underset(|)overset(H)overset(|)(C )-Cl(g)rarrC(g)+2H(g)+2Cl(g)`
[Use table given in Appendix for standard enthalpy of formation]

Explanation

The given reaction represents a process in which chemical bonds are broken and constituent atoms are are produced. Clearly this is a case atomisation of `CH_(2)Cl_(2)(g)` as in this case no new bond is formed. Thus
`{:("Bond energy in",,,,"Bond energy out"),("(to break bonds)",,,,"(to form bond)"),(2DeltaH^(Θ)(C-H)=2xx413 kJ mol^(-1),,,,"No bond is"),(2DeltaH^(Θ)(C-Cl)=2xx328 kJ mol^(-1),,,,"formed"DeltaH^(Θ)),(Total=1482 kJ mol^(-1),,,,"(Out) is zero"):}`
`DeltaH^(Θ)= Sigma BE` of Reactants `-Sigma BE` of products
`=1482 kJ mol^(-1)-0=1482 kJ mol^(-1)`