Question

In the CO 2 test, what is the milky solid (white solid in suspension) that forms in the li solution? Use chemical equations to show the formation of the white solid. 4. In the test for l, you use methylene chloride. How does the density of methylene chloride compare to the density of water?

Answer 1

3. In the CO₃^2- test, we first add dilute acid (for example HCl) to the salt or its aqueous solution (containing the carbonate ion). The carbonate ion reacts with the acid to form CO₂ gas.

$CO_3^{2-}(aq)+2H^+(aq)\rightarrow CO_2(g)+H_2O(l)$

CO₂ when bubbled through the limewater solution forms the milky solid (white solid in suspension) which is Calcium carbonate. It is formed by reaction of the CO₂ (released in above reaction) with limewater (Ca(OH)₂).

$CO_2(g)+Ca(OH)_2(aq)\rightarrow CaCO_3(s)+H_2O(l)$