Question

Estimate the value $x$ to balance the given equation.

$M{g}_3{N}_2\left(aq\right)+x{H}_{2}O\left(l\right)\to 3Mg\left(OH{)}_2\right(aq)+2N{H}_3(g)$

• A. 2
• B. 4
• C. 6
• D. 8

Answer 1

The correct option is C 6

A balanced chemical equation has an equal number of atoms on both the sides of a chemical reaction.

For the given equation: $M{g}_3{N}_2\left(aq\right)+x{H}_{2}O\left(l\right)\to 3Mg\left(OH{)}_2\right(aq)+2N{H}_3(g)$
Reactants Products

Elements	No. of atoms	Elements	No. of atoms
Mg	3	Mg	3
N	2	N	2
H	2	H	12
O	1	O	6

Here, Mg and N atoms are balanced at both sides. To balance H and O atoms, the value of $x$ should be 6.

Hence, the balanced equation is:
$M{g}_3{N}_2\left(aq\right)+6H_{2}O\left(l\right)\to 3Mg\left(OH{)}_2\right(aq)+2N{H}_3(g)$