Chapter 20, Problem 20.84SP

Interpretation Introduction

Interpretation:

Interpret the mass change in grams/ mole of ammonia accompanying the formation of ammonia from ${\text{H}}_{\text{2}}$ and ${\text{N}}_{\text{2}}$.

${\text{N}}_{\text{2(g)}}{\text{ + 3H}}_{\text{2(g)}}\stackrel{}{\to }{\text{2 NH}}_{\text{3(g)}}\text{ ΔH° = -92}\text{.2kJ}$

Concept introduction:

A chemical reaction involves the conversion of certain chemical compounds to certain new substances which are known as product and the substances which involve in the chemical reaction are known as a reactant.

Hence, chemical reactions can be considered as the conversion of reactant to a product through making or breaking of certain chemical bonds.

The energy change of reaction is associated with the mass change with Einstein’s mass − energy equation:

$\text{E= }\Delta {\text{m × c}}^{\text{2}}$

The mass change ( $\Delta \text{m}$ ) can be calculated as the difference in the mass of product and mass of reactant.