Question

Estimate enthalpy change : CHCL3 + O --> COCL2 + HCL

Answer 1

At what? Remember that enthalpy depends on quite some factors. Remember that the natural variables of enthalpy are pressure and entropy.

Answer 2

The most normal in such a question would be to calculate the enthalpy at standard pressure: \(10^{5} \sf Pa\) and 298 K

Answer 3

In such case we write:
\[\Large \Delta _{r}H^\Theta=\sum_{i}^{}v _{i} ~ \Delta_{f}H^{\Theta}(i)\]
Ref: Me - lots of work in thermodynamics.