Chapter 10, Problem 5STP

Interpretation Introduction

Interpretation: To identify the compound that have the largest percent by mass of nitrogen.

Concept Introduction: The type of chemical reaction in which the count of atoms will be identical on both sides of the reaction is named as a balanced chemical reaction.

Answer to Problem 5STP

(A)

Explanation of Solution

Mass percentage can be determined by using the formula:

  $\text{Mass}\text{percentage=}\frac{\text{mass}\text{of}\text{elements}}{\text{mass}\text{of}\text{compound}}\text{×100}$

a)The given compound is ${\text{N}}_{\text{2}}\text{O}$

Mass of nitrogen =28 g/mol

Mass of ${\text{N}}_{\text{2}}\text{O}$ = 44 g/mol

Put the values of given data in above equation.

  $\begin{array}{c}\text{Mass}\text{percentage=}\frac{\text{mass}\text{of}\text{elements}}{\text{mass}\text{of}\text{compound}}\text{×10}\\ \text{=}\frac{\text{28×100}}{\text{44}}\\ \text{=63\%}\end{array}$

b) The given compound is $\text{NO}$

Mass of nitrogen =28 g/mol

Mass of $\text{NO}$ =30 g/mol

Put the values of given data in above equation.

  $\begin{array}{c}\text{Mass}\text{percentage=}\frac{\text{mass}\text{of}\text{elements}}{\text{mass}\text{of}\text{compound}}\text{×10}\\ \text{=}\frac{\text{28×100}}{30}\\ \text{=46}\text{.6\%}\end{array}$

c) The given compound is ${\text{NO}}_2$

Mass of nitrogen =14 g/mol

Mass of ${\text{NO}}_2$ = 46 g/mol

Put the values of given data in above equation.

  $\begin{array}{c}\text{Mass}\text{percentage=}\frac{\text{mass}\text{of}\text{elements}}{\text{mass}\text{of}\text{compound}}\text{×10}\\ \text{=}\frac{\text{14×100}}{46}\\ \text{=30\%}\end{array}$

e) The given compound is ${\text{N}}_2{\text{O}}_4$

Mass of nitrogen =28 g/mol

Mass of ${\text{N}}_2{\text{O}}_4$ = 92 g/mol

Put the values of given data in above equation.

  $\begin{array}{c}\text{Mass}\text{percentage=}\frac{\text{mass}\text{of}\text{elements}}{\text{mass}\text{of}\text{compound}}\text{×10}\\ \text{=}\frac{\text{28×100}}{92}\\ \text{=30\%}\end{array}$

d) The given compound is ${\text{N}}_2{\text{O}}_3$

Mass of nitrogen =28 g/mol

Mass of ${\text{N}}_2{\text{O}}_3$ = 76 g/mol

Put the values of given data in above equation.

  $\begin{array}{c}\text{Mass}\text{percentage=}\frac{\text{mass}\text{of}\text{elements}}{\text{mass}\text{of}\text{compound}}\text{×10}\\ \text{=}\frac{\text{28×100}}{76}\\ \text{=36}\text{.8\%}\end{array}$

After calculating the mass percentage of nitrogen in each case the compound having largest mass percentage of nitrogen is option A.