# Why does calcium carbonate undergo mass loss upon heating?

Dec 30, 2016

Because of gas evolution...

#### Explanation:

$C a C {O}_{3} \left(s\right) + \Delta \rightarrow C a O \left(s\right) + C {O}_{2} \left(g\right) \uparrow$

Clearly, the carbonate is decomposed, with concomitant loss of mass as carbon dioxide gas. Typically, the product gas will be shunted to a solution of lime water ($C a {\left(O H\right)}_{2}$), where the carbonate will be reconstituted:

$C a {\left(O H\right)}_{2} \left(a q\right) + C {O}_{2} \left(g\right) \rightarrow C a C {O}_{3} \left(s\right) + {H}_{2} O \left(l\right)$

Are mass and charge conserved in both reactions? Should they be?