Enthaply change

[Clinicall]

---

Members do not see this ad.

If reaction 1 is 2(H2) --> 4H is -870 Kj/mol
And if reaction 2 is C + 4H --> CH4 is +794 Kj/mol

Then the Enthaply change for the reaction is -76 Kj/mol

But if it asks for the change of Enthaply to generate 2 moles of CH4, is it -152 Kj/mol (doubled) or is it still -76 Kj/mol. I thought it would be double, but an app that I'm using says that I'm wrong, can someone confirm this or if this app is screwing me.

 

[DrDashInd]

It would be double, but it would be -152 KJ, not KJ/mol. Maybe that's the problem?

 

[Clinicall]

Oops, yes you're right, thats what I meant, but it still said it would only be -76. Maybe I should ditch this app before it gives me too many other false answers. Thanks for confirming

 

[ClemsonFirst]

What app is it?

 

[MedGrl@2022]

If reaction 1 is 2(H2) --> 4H is -870 Kj/mol
And if reaction 2 is C + 4H --> CH4 is +794 Kj/mol

Then the Enthaply change for the reaction is -76 Kj/mol

But if it asks for the change of Enthaply to generate 2 moles of CH4, is it -152 Kj/mol (doubled) or is it still -76 Kj/mol. I thought it would be double, but an app that I'm using says that I'm wrong, can someone confirm this or if this app is screwing me.

Enthalpy is an extensive property... so yes it would be -152 KJ