Question

Balance the following reaction.
 $\text{Na+}{\text{H}}_{\text{2}}\text{O}\to \text{NaOH+}{\text{H}}_{\text{2}}$
(A) $\text{2Na+2}{\text{H}}_{\text{2}}\text{O}\to 2\text{NaOH+}{\text{H}}_{\text{2}}$
(B) $\text{Na+}{\text{H}}_{\text{2}}\text{O}\to \text{NaOH+2}{\text{H}}_{\text{2}}$
(C) $\text{2Na+}{\text{H}}_{\text{2}}\text{O}\to \text{NaOH+}{\text{H}}_{\text{2}}$
(D) $\text{Na+}\frac{1}{2}{\text{H}}_{\text{2}}\text{O}\to \text{NaOH+}{\text{H}}_{\text{2}}$

Answer 1

Hint: In a balance reaction the number of molecules of reactant should be equal to the product molecule.
- In this reaction equal sodium and oxygen atoms are present on both sides. Two hydrogen atoms are present on the left side of the reaction but on the right side three hydrogen atoms are present. So to balance this reaction we will have to balance the hydrogen atom both the sides of the reaction.

Complete step by step answer:
(A) In this reaction both sides of the reaction all the three atoms are balanced, so this reaction will be the correct answer.
(B) In this reaction sodium ion is present in the balance condition but hydrogen and oxygen are not balanced, so this will not be a balanced reaction.
(C) In this reaction only oxygen atoms are balanced, but nitrogen and hydrogen are not balanced, so this will not be a balanced condition.
(D) In this reaction only sodium atoms are present in balanced condition in both the sides of the reaction but oxygen and hydrogen are not in balanced condition, so this will be an unbalanced reaction.
So, the correct answer is “Option A”.

Note: Simple or elementary reaction is balanced by balancing their stoichiometry coefficient of the entire reactant and product molecule. While redox reactions are balanced by two methods; oxidation number changes method and ion electron method.