# Question #ea16b

Mar 10, 2017

Carbonates like limestone and marble.

#### Explanation:

Limestone is made of Calcium Carbonate $C a C {O}_{3}$
Marble is the metamorphic form of limestone being harder but having the same chemical formula $C a C {O}_{3}$

When acid is added to a carbonate the compound breaks down into Carbon Dioxide $C {O}_{2}$ and water${H}_{2} O$ leaving a residue of Calcium Chloride$C a C {l}_{2}$

$2 H C l = = = C a C {l}_{2} + {H}_{2} O + C {O}_{2}$

The fizz of the carbon dioxide gas being released is a easily
recognized indicator of the presence of the carbonate. This makes the acid test a good way of identifying limestone and marble.