How does Magnesium Oxide React with Water?

How do temperature and other external factors affect magnesium reactivity with water? This article explores all of that.

Introduction:

The basic reason for natural or synthesized chemical bonding is that an element's atoms become more stable through electron loss, gain, and sharing. It’s not just us who love stability, everyone loves stability so do the atoms. Because most elements are unstable and chemically reactive (except noble gases), they may share electrons at their outer energy levels, this tends to form chemical compounds of different elements with different molecular structures.

When this occurs, each atom's outermost electron shell creates a magic number called the oxidation number. The same concept can be explained as an element's reaction is determined by its electron count in its atomic structure. Examining the various clusters in an atom explores the elements' tendency of potential reactions.

Water, an extremely important solvent from mother nature can function as both an acid (a proton donor chemical entity) and a base (a proton acceptor chemical entity). This is one of its most significant chemical characteristics which have a direct effect on its chemical properties.

Magnesium Oxide and Water

Water is a well-known ionic compound that acts as a solvent for many solutes out there in nature.

Magnesium, a vital mineral for us does show significant reactivity towards the water but has sluggish reactivity values. But magnesium reactivity with water increases in the presence of oxygen giving away magnesium hydroxide and hydrogen gas:

Mg + 2H₂O    →    Mg (OH)₂ + H₂

Magnesium’s oxide or MgO, the magnesium oxide or magnesia which is easily found as periclase in nature doesn’t readily react with water at ambient temperatures but magnesium reactivity with water increases when more oxygen is introduced in the solution and temperatures are increased. At 120 degrees Celsius temperature, both react as shown in the reaction below. The Magnesium hydroxide is slightly soluble. This oxide and the reaction itself can be reversed by reheating the solution again.

MgO + H₂O    →     Mg(OH)₂

The above reaction is also an example of a neutralization reaction. Such reactions are those in which an acid and a base react to give away salts and water. In the above reaction, water behaves as an acid and carries out a neutralization reaction. This property is one of its greatest characteristics and has direct and indirect significance in many biological reactions, industrial processes, and academic studies of elements in general.

As mentioned before, the reactivity of magnesium increases with the presence of oxygen, which is why water fails to put out magnesium flames in the case of such fire. However, it shows strong reactivity with hydrogen which is why magnesium reacts violently with hydrogen gas when water is used to put out magnesium flames in a fire. Also, magnesium will continue even after all oxygen is gone. After that, it combines with atmospheric nitrogen to create magnesium nitride (Mg₃N₂).

The reactivity of MgO can be increased like any other element by introducing catalysts (like Transition metals with their compounds and homogenous catalysts etc.) but the reaction itself is categorized as a forward reaction that doesn’t require catalysts to increase reactivity. Temperature itself is enough to increase the reactivity.

First, the increase in temperature ramps up the chances of collisions between the atoms of two participants in the reaction. Moreover, the increase in temperature allows the atoms of this oxide and water ionic molecules to overcome the activation energy barrier and proceed to form products. The increase of reactivity with temperature can also be explained by the Arrhenius equation as well.

Wrapping Up:

The magnesium reactivity with water can be increased with temperature and also with certain catalysts but this catalyst is not necessary as the reaction is a straight straightforward neutralization reaction. The products of the reaction can be reversed when Magnesium oxide and water are allowed to react.