# How would you balance the following equation: CaO3 --> CaO+CO2?

Jan 9, 2016

You have a typo in your question:

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

#### Explanation:

If you HEAT a carbonate sufficiently, the reaction above occurs.

We could reverse this reaction by bubbling carbon dioxide thru calcium hydroxide:

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

In fact, this second reaction is a test for carbon dioxide. Carbon dioxide gas should turn limewater ($C a {\left(O H\right)}_{2} \left(a q\right)$ milky (i.e. a precipitate of white $C a C {O}_{3}$ occurs). When you do this reaction yourself in the lab, you should always do a test first: i.e. treat saturated calcium hydroxide with carbonated water (i.e. water with saturated with $C {O}_{2}$). What do you see?

Are these reactions balanced? How do you know?