Magnesium bicarbonate doesn't actually form hydroxide upon boiling. Instead, it decomposes into other compounds. Here's why:

Magnesium bicarbonate (Mg(HCO3)2) is unstable in solution and readily decomposes upon heating.

The decomposition reaction:

Mg(HCO3)2 (aq) → MgCO3 (s) + H2O (l) + CO2 (g)

Here's what happens:

* Decomposition: When you heat the solution, the magnesium bicarbonate breaks down into magnesium carbonate (MgCO3), water (H2O), and carbon dioxide (CO2).

* Insolubility: Magnesium carbonate is insoluble in water, so it precipitates out of solution as a white solid.

* Carbon dioxide escape: The carbon dioxide gas bubbles out of the solution.

Therefore, instead of forming magnesium hydroxide (Mg(OH)2), boiling a magnesium bicarbonate solution leads to the formation of magnesium carbonate and the release of carbon dioxide.

Why not hydroxide?

Magnesium hydroxide (Mg(OH)2) is a strong base, while magnesium bicarbonate is a weak base. Upon decomposition, the bicarbonate ion (HCO3-) loses a proton (H+) to form carbonate (CO3^2-) and carbon dioxide (CO2). The resulting carbonate is not basic enough to deprotonate water to form hydroxide ions.

In summary, boiling magnesium bicarbonate does not result in hydroxide formation but rather in the decomposition of the bicarbonate into magnesium carbonate, water, and carbon dioxide.