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is ΔrHθ same as ΔH?

In reference to hess's law
ΔHrΘ is the standard enthalpy change of reaction

ΔH is enthalpy change
Reply 2
Original post by BobbJo
ΔHrΘ is the standard enthalpy change of reaction

ΔH is enthalpy change


What I mean is that if you had an equation from reactants to products, the ΔH or ΔrHθ would always be the arrow going from reactants to products. There wouldn't be any arrows going down or up called ΔH or ΔrHθ if that makes sense?
Original post by foxstudy
What I mean is that if you had an equation from reactants to products, the ΔH or ΔrHθ would always be the arrow going from reactants to products. There wouldn't be any arrows going down or up called ΔH or ΔrHθ if that makes sense?

The arrow goes from reactant to products only so one direction only
Reply 4
Original post by BobbJo
The arrow goes from reactant to products only so one direction only


I understand that, but if you had a ΔrHθ, would that arrow be going directly from reactants to products ?
Original post by foxstudy
I understand that, but if you had a ΔrHθ, would that arrow be going directly from reactants to products ?

Yes. It should be written ΔHrΘ

https://en.wikipedia.org/wiki/Standard_enthalpy_of_reaction
(denoted by ... )

Provide the question if you are unsure of it
They’re very subtly different, but in relation to most Hess’s law questions they’re the same.
Thé standard enthalpy of reaction, is the enthalpy change of a reaction in standard conditions.
The enthalpy change is just that, the change inenthalpy during a process. Delta H just describes how energy changes, it could be in relation to lattice formation, solution or indeed a reaction. Normally for a delta H thats not in relation to a reaction you would use the specific notation, so most people assume when you see delta H, it’s analogous to the enthalpy of reaction
Original post by foxstudy
In reference to hess's law

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