3 replies to this topic

[Tolinorton]

Why is heat produced when we add water (H2O) to calcium oxide (CaO)?

[breizh]

Hi,

From literature :

 

CaO (s) + H2O (l)  --- >     Ca (OH) 2 (aq) (∆Hr = −63.7 kJ/mol of CaO)

exothermic reaction

Check for slaking of lime using your favorite search engine .

Breizh 

Edited by breizh, 01 January 2020 - 06:20 AM.

[latexman]

The elements Ca, O, H changed to a lower energy state giving that energy to the environment.  It became a more stable (lower energy) form.

[Chemitofreak]

The elements Ca, O, H changed to a lower energy state giving that energy to the environment.  It became a more stable (lower energy) form.

 

This is the best and simplest explanation possible. Even a layman can understand that...!