Question

How would we represent the reaction of magnesium bicarbonate with hydrochloric acid?

Answer 1

Hint: We know that both magnesium bicarbonate and hydrochloric acid are soluble in aqueous solution i.e., both the compounds have a tendency to completely dissociate to form respective ions. These ions in the aqueous solution will react to give respective products.

Complete Step By Step Answer:
In an aqueous solution dissociation of magnesium bicarbonate will take place as follows:
 $ Mg{{(HC{{O}_{3}})}_{2}}(aq.)\to M{{g}^{2+}}(aq.)+2HCO_{3}^{-}(aq.) $
And hydrochloric acid will dissociate as follows:
 $ HCl(aq.)\to {{H}^{+}}(aq.)+C{{l}^{-}}(aq.) $
Now, when these two solutions are mixed, a chemical reaction will occur to produce a soluble salt of magnesium chloride and carbonic acid i.e., $ {{H}_{2}}C{{O}_{3}} $ . The reaction will take place as follows:
 $ Mg{{(HC{{O}_{3}})}_{2}}(aq.)+2HCl\to MgC{{l}_{2}}(aq.)+2{{H}_{2}}C{{O}_{3}}(aq.) $
Now, we know that carbonic acid is very unstable in aqueous solution and thus, tends to decompose to give carbon dioxide and water as per the following reaction:
 $ {{H}_{2}}C{{O}_{3}}\to C{{O}_{2}}(g)+{{H}_{2}}O(l) $
Hence, the overall chemical equation for the reaction of magnesium bicarbonate with hydrochloric acid will be as follows:
 $ Mg{{(HC{{O}_{3}})}_{2}}(aq.)+2HCl(aq.)\to MgC{{l}_{2}}(aq.)+2{{H}_{2}}O(l)+2C{{O}_{2}}(g) $
Thus, we can conclude that on reaction of magnesium bicarbonate with hydrochloric acid, magnesium chloride is formed along with the removal of water and carbon dioxide.

Note:
Remember to balance the chemical equation at each step to accurately represent the number of moles of each molecule exhausted during the reaction. It is important to note that for a chemical reaction, the ions which do not participate in the reaction and are found in solution both before as well as after the reaction are known as spectator ions. For the given chemical reaction, magnesium ion i.e., $ M{{g}^{2+}} $ and chloride ion i.e., $ C{{l}^{-}} $ are the spectator ions.