Chapter 9.1, Problem 12SSC

Interpretation Introduction

Interpretation:

Whether the following equation is balanced or not needs to be determined and if the equation is not balanced, the coefficients to balance the equation need to be given.

$2{\text{K}}_{\text{2}}{\text{CrO}}_4(aq)+{\text{Pb(NO}}_3{\text{)}}_2(aq)\to 2{\text{KNO}}_{\text{3}}(aq)+{\text{PbCrO}}_{\text{4}}(s)$

Concept introduction:

A chemical equation is termed as balanced chemical equation if the number of atoms of every element is equal in the reactant side and product side. One example is,

${\text{N}}_{\text{2}}+3{\text{H}}_{\text{2}}\to 2{\text{NH}}_{\text{3}}$

In the reaction, number of nitrogen atom is 2 and the number of hydrogen atom is 6 in both the reactant and product side. So, the equation is balanced chemical equation.

Answer to Problem 12SSC

The given equation is not a balanced equation.

The balanced equation is,

${\text{K}}_{\text{2}}{\text{CrO}}_4(aq)+{\text{Pb(NO}}_3{\text{)}}_2(aq)\to 2{\text{KNO}}_{\text{3}}(aq)+{\text{PbCrO}}_{\text{4}}(s)$

Explanation of Solution

The given equation is as follows:

$2{\text{K}}_{\text{2}}{\text{CrO}}_4(aq)+{\text{Pb(NO}}_3{\text{)}}_2(aq)\to 2{\text{KNO}}_{\text{3}}(aq)+{\text{PbCrO}}_{\text{4}}(s)$

The equation is not balanced equation as the number of atoms of K, O is different in both sides of the reaction.

To balance the equation, coefficient 2 must be added to the ${\text{KNO}}_{\text{3}}$ of the product side. Now the number of atoms of the all the elements is equal in both reactant and product side. So, the balanced equation is,

${\text{K}}_{\text{2}}{\text{CrO}}_4(aq)+{\text{Pb(NO}}_3{\text{)}}_2(aq)\to 2{\text{KNO}}_{\text{3}}(aq)+{\text{PbCrO}}_{\text{4}}(s)$

Conclusion

To check a reaction is balanced or not, count the number of atoms of every element in both sides of the reaction.