# When dilute hydrochloric acid is placed on fock limestone and the non-sedimentary rock marble, a bubbling reaction occurs with both. What would this indicate?

Dec 22, 2017

Both limestone and marble are forms of calcium carbonate.... And the bubbling indicates the evolution a gas, but which one?

#### Explanation:

And calcium carbonate, pretty insoluble stuff, undergoes a reaction with strong acids:

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

And of course liberation of carbon dioxide would account for the bubbling observed in the reaction.

The gases that bubbled off the reaction could be bled into a solution of lime-water, i.e. $C a {\left(O H\right)}_{2} \left(a q\right)$...and the carbonate would reprecipitate...

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

Surely you have done practicals to examine these reactions?