Question

How would you balance the following equation:
${\text{Mg + }}{{\text{O}}_{\text{2}}} \to {\text{MgO}}$

Answer 1

Hint For balancing any chemical equation, we have to maintain equal molecularity of each atom present in the chemical reaction on the reactant side as well as on the product side of the reaction.

Complete step by step solution:
The chemical equation is ${\text{Mg + }}{{\text{O}}_{\text{2}}} \to {\text{MgO}}$.
For balancing the above given equation we have to consider following points in mind:
-First we calculate the number of each atom on the left hand side as well as on the right hand side of the given chemical equation.
-So on the left hand side or reactant side as well as on the right hand side or product side of the chemical reaction one magnesium (${\text{Mg}}$) atom is present.
-On the left hand side two atoms of oxygen (${\text{O}}$) are present but on the right hand side only one oxygen atom is present which is not correct.
So, we will balance the above given reaction by the following manner so that each atom will have the same molecularity on the reactant side as well as on the product of the reaction. And balanced equation is shown as:
${\text{2Mg + }}{{\text{O}}_{\text{2}}} \to 2{\text{MgO}}$
-In the above balanced equation two magnesium (${\text{Mg}}$) atoms and two oxygen (${\text{O}}$) atoms are present on the left hand side as well as on the right hand side of the chemical reaction also.

Note: Here some of you may think order of reaction and molecularity of reaction are the same things but that will be true only for the elementary (single step reaction) reactions only.