Chapter 11.1, Problem 5SSC

Interpretation Introduction

Interpretation:

The mass of reactants and products in a chemical reaction are to be compared and their relationship is to be stated.

Concept introduction:

The substances that undergo chemical reaction are defined as reactants and the substances thus formed are known as products.

Answer to Problem 5SSC

The coefficients of balanced chemical equation help in comparing the moles and masses of reactants and products. The mass of reactants and products is equal in a chemical reaction.

Explanation of Solution

According to law of conservation of mass it is not possible to form the mass or to destroy the mass. The mass always remains conserved. The balancing of chemical equation equalizes the number of atoms of each element at the reactant side as well as at the product side. Thus, this balancing ultimately makes the mass of each species equal on both the sides of the chemical equation. The mass of reactants is always equal to mass of products in a balanced chemical equation as shown below.

Let a balanced chemical equation is shown below.

${\text{N}}_{\text{2}}\left(g\right)+3{\text{H}}_2\left(g\right)\to {\text{2NH}}_{\text{3}}\left(g\right)$

Total mass of reactants and products is given as shown below.

$\begin{array}{c}\text{Total mass of reactants}={\text{Mass of N}}_{\text{2}}+{\text{Mass of H}}_{\text{2}}\\ =28.0\text{g}+6.0\text{g}\\ =\text{34}\text{.0}\text{g}\end{array}$

$\begin{array}{c}\text{Total mass of products}={\text{Mass of NH}}_{\text{3}}\\ =\text{34}\text{.0}\text{g}\end{array}$

Here, the mass of reactants is equal to mass of the products.

Conclusion

The coefficients of balanced chemical equation help in comparing the moles and masses of reactants and products. The mass of reactants and products is equal in a chemical reaction.