The Story Behind Hess Law

Aug 2019
2
0
USA
My book introduces Thermochemistry with the concept of heat and how a calorimeter works. After that, it explains the story behind Hess Law and says that one of the reasons it was created is because a calorimeter can't calculate fast chemical reactions, but it doesn't really say the problem with it. Why can't it calculate fast chemical reactions? Won't the water in the calorimeter heat up or cool down after some time?
 
May 2015
34
1
New Delhi -India
My book introduces Thermochemistry with the concept of heat and how a calorimeter works. After that, it explains the story behind Hess Law and says that one of the reasons it was created is because a calorimeter can't calculate fast chemical reactions, but it doesn't really say the problem with it. Why can't it calculate fast chemical reactions? Won't the water in the calorimeter heat up or cool down after some time?
During fast reaction heat released per unit time is more which results in more loss of heat to surroundings.
 
Aug 2019
2
0
USA
Why there is more loss to the surroundings? Won't the heat be used to elevate the water temperature?
 
May 2015
34
1
New Delhi -India
When all heat is released abruptly in less time then some heat is lost to surroundings before it is gained by water.