Enthalpy change in a reaction

[KiaraTenorio_14B]

How does enthalpy change through out a chemical reaction to obtain the net change?

[AnoushkaBhat2J]

Each intermediate reaction can have a different enthalpy, and you can add them all together to find the total change in enthalpy. So even though some intermediate reactions may have a +deltaH, meaning they are endothermic, the overall reaction could have a negative delta H (exothermic).

[Alison King 3L]

Since enthalpy is a state property, we can use the different enthalpies of intermediate reactions to find the final net change because the path to get to the final reaction doesn't matter.

[Srikar_Chintala_1E]

Since enthalpy is a state function, you can just subtract the final state by the initial state to find the net. How you get there does not really matter as it is a state function.

[Vy Le 1G]

Hi Kiara,

Like others mentioned, enthalpy is a state function so you can just add or subtract the different enthalpies to get the net change. To specifically answer your question of HOW it changes in a reaction, this is due to the fact reactions can involve multi-step processes. One reaction may be endothermic while the second step/reaction may be exothermic. Therefore, in order to get the enthalpy for the full process, you need to find the net enthalpy.

Hopefully this clarified the concept!