Question

How will you prepare the following?
Magnesium hydrogen carbonate from magnesium chloride.

Answer 1

We know that magnesium chloride is a white colored crystalline substance having the chemical formula ${\text{MgC}}{{\text{l}}_{\text{2}}}$. It is a type of ionic halides and is highly soluble in water. Here, we have to prepare magnesium hydrogen carbonate from magnesium chloride.

Complete step by step answer:
First we will discuss magnesium hydrogen carbonate in detail. It is a bicarbonate salt of Mg (Magnesium). The chemical formula of magnesium hydrogen carbonate is ${\text{Mg}}{\left( {{\text{HC}}{{\text{O}}_{\text{3}}}} \right)_2}$. Let’s discuss the preparation of magnesium hydrogen carbonate from magnesium chloride. There are two steps in the production of magnesium hydrogen carbonate.
First step is the preparation of magnesium hydroxide from magnesium chloride. Magnesium hydroxide when reacts with calcium hydroxide produces magnesium hydroxide. The reaction can be shown as below:
${\text{MgC}}{{\text{l}}_{\text{2}}} + {\text{Ca}}{\left( {{\text{OH}}} \right)_{\text{2}}} \to {\text{Mg}}{\left( {{\text{OH}}} \right)_{\text{2}}} + {\text{CaC}}{{\text{l}}_{\text{2}}}$
Next step is the reaction of magnesium hydroxide with pressurized carbon dioxide resulting in a solution of magnesium bicarbonate. The reaction is shown as below:
${\text{Mg}}{\left( {{\text{OH}}} \right)_{\text{2}}} + 2{\text{C}}{{\text{O}}_{\text{2}}} \to {\text{Mg}}{\left( {{\text{HC}}{{\text{O}}_{\text{3}}}} \right)_2}$
So, in this way magnesium hydrogen carbonate is prepared from magnesium chloride.

Additional Information:
Let’s discuss some important points regarding magnesium chloride. Magnesium chloride can be prepared by the Dow process. In this process, magnesium hydroxide reacts with hydrogen chloride to produce magnesium chloride and water.
${\text{Mg}}{\left( {{\text{OH}}} \right)_{\text{2}}} + {\text{HCl}} \to {\text{MgC}}{{\text{l}}_{\text{2}}} + 2{{\text{H}}_{\text{2}}}{\text{O}}$
There are many uses of magnesium chloride such as it is used in dust control, it is used in stabilization of soil and wind erosion.

Note: It is to be noted that there are many methods of preparation of magnesium hydrogen carbonate. One method is the reaction of magnesium acetate and sodium bicarbonate. The reaction is,
${\text{Mg}}{\left( {{\text{C}}{{\text{H}}_{\text{3}}}{\text{COO}}} \right)_2} + 2{\text{NaHC}}{{\text{O}}_{\text{3}}} \to {\text{Mg}}{\left( {{\text{HC}}{{\text{O}}_{\text{3}}}} \right)_2} + 2{\text{C}}{{\text{H}}_{\text{3}}}{\text{COONa}}$