Why is the enthalpy of formation method the most accurate?

[Anthony_3C]

Why is the ∆Hºf method the most accurate when calculating ∆H for a rxn? (this is what dr. Lavelle said) Does this mean that Hess's law is less accurate? But why if Hess's law also uses standard enthalpy of rxn(although not formation)?

[Valerie Tran 2B]

I am also confused, wouldn't the method used depend on what's given? Why would any one method be more accurate?

[Bella Wachter 1A]

I believe he is referencing the fact that the bond enthalpy method of calculating ∆H is less accurate than the ∆H˚f method because it uses average bond enthalpies - which are not entirely accurate, and are estimates to the actual bond enthalpy of a bond in a specific molecule.

[Devin Patel 2D]

The enthalpy of formation is more accurate compared to using bond enthalpies because the bond enthalpy values given are the average bond enthalpies. These averages are just estimates so they aren't the most accurate. I believe Hess's law is as accurate using enthalpy of formation.

[kateraelDis1L]

I think it it more accurate because it's the energy associated with the formation of one mole of a compound from its basic elements in standard states. These values are less of an approximation.

[Edgar Velazquez 2K]

I think the point he was trying to make is that bond enthalpies are the least accurate (since the value is based on averages and not the actual bond enthalpies of the specific molecules), so any other method would be more accurate.