Chapter 2, Problem 2.88P

a)

Interpretation Introduction

Interpretation:Molecular mass of the below-mentioned depiction is to be given. Also, correct name of compound should be done if it is named incorrectly.

  

Concept introduction: In the molecular formula, the exact number and type of constituent atoms are shown. Type of constituent atoms is represented by their atomic symbols and number of each constituent atom is represented in the right subscript of its atomic symbol. In a hypothetical molecule ${\text{A}}_{\text{x}}{\text{B}}_{\text{y}}$ , x number of $\text{A}$ atom and y number of $\text{B}$ atom combines to form the compound.

Formula to calculate molecular mass of ${\text{A}}_{\text{x}}{\text{B}}_{\text{y}}$ is as follows:

  $\text{Molecular}\text{mass}\text{of}{\text{A}}_{\text{x}}{\text{B}}_{\text{y}}\text{=}\left(\begin{array}{l}\left(\text{x}\right)\left(\text{Atomic}\text{mass}\text{of}\text{A}\right)\text{+}\\ \left(\text{y}\right)\left(\text{Atomic}\text{mass}\text{of}\text{B}\right)\end{array}\right)$

Explanation of Solution

In the depiction three fluorine atoms are connected with central atom bromine. Hence the molecular formula of the molecules is ${\text{BrF}}_{\text{3}}$ .

Molecular mass of ${\text{BrF}}_{\text{3}}$ is calculated as follows:

  $\begin{array}{c}\text{Molecular}\text{mass}\text{of}{\text{BrF}}_3=\left(\begin{array}{l}\left(1\right)\left(\text{Atomic}\text{mass}\text{of}\text{Br}\right)+\\ \left(3\right)\left(\text{Atomic}\text{mass}\text{of}\text{F}\right)\end{array}\right)\\ =\left[\left(\text{1}\right)\left(79.90\text{ amu}\right)+\left(3\right)\left(19\text{ amu}\right)\right]\\ =79.90\text{ amu}+57\text{ amu}\\ =136.90\text{ amu}\end{array}$

Name of the compound ${\text{BrF}}_{\text{3}}$ is bromine trifluoride.

b)

Interpretation Introduction

Interpretation: Molecular mass of the below-mentioned depiction is to be given. Also, correct name of compound should be done if it is named incorrectly.

  

Concept introduction:In the molecular formula, the exact number and type of constituent atoms are shown. Type of constituent atoms is represented by their atomic symbols and number of each constituent atom is represented in the right subscript of its atomic symbol. In a hypothetical molecule ${\text{A}}_{\text{x}}{\text{B}}_{\text{y}}$ , x number of $\text{A}$ atom and y number of $\text{B}$ atom combines to form the compound.

Formula to calculate molecular mass of ${\text{A}}_{\text{x}}{\text{B}}_{\text{y}}$ is as follows:

  $\text{Molecular}\text{mass}\text{of}{\text{A}}_{\text{x}}{\text{B}}_{\text{y}}\text{=}\left(\begin{array}{l}\left(\text{x}\right)\left(\text{Atomic}\text{mass}\text{of}\text{A}\right)\text{+}\\ \left(\text{y}\right)\left(\text{Atomic}\text{mass}\text{of}\text{B}\right)\end{array}\right)$

Explanation of Solution

In the depiction two chlorine atoms are connected with central atom sulfur. Hence the molecular formula of the molecules is ${\text{SCl}}_2$ .

Molecular mass of ${\text{SCl}}_2$ is calculated as follows:

  $\begin{array}{c}\text{Molecular}\text{mass}\text{of}{\text{SCl}}_2=\left(\begin{array}{l}\left(1\right)\left(\text{Atomic}\text{mass}\text{of}\text{S}\right)+\\ \left(2\right)\left(\text{Atomic}\text{mass}\text{of}\text{Cl}\right)\end{array}\right)\\ =\left[\left(\text{1}\right)\left(32.06\text{ amu}\right)+\left(2\right)\left(35.45\text{ amu}\right)\right]\\ =32.06\text{ amu}+70.90\text{ amu}\\ =102.96\text{ amu}\end{array}$

Name of the compound ${\text{SCl}}_2$ is sulfur dichloride.

c)

Interpretation Introduction

Interpretation: Molecular mass of the below-mentioned depiction is to be given. Also, correct name of compound should be done if it is named incorrectly.

  

Concept introduction:In the molecular formula, the exact number and type of constituent atoms are shown. Type of constituent atoms is represented by their atomic symbols and number of each constituent atom is represented in the right subscript of its atomic symbol. In a hypothetical molecule ${\text{A}}_{\text{x}}{\text{B}}_{\text{y}}$ , x number of $\text{A}$ atom and y number of $\text{B}$ atom combines to form the compound.

Formula to calculate molecular mass of ${\text{A}}_{\text{x}}{\text{B}}_{\text{y}}$ is as follows:

  $\text{Molecular}\text{mass}\text{of}{\text{A}}_{\text{x}}{\text{B}}_{\text{y}}\text{=}\left(\begin{array}{l}\left(\text{x}\right)\left(\text{Atomic}\text{mass}\text{of}\text{A}\right)\text{+}\\ \left(\text{y}\right)\left(\text{Atomic}\text{mass}\text{of}\text{B}\right)\end{array}\right)$

Explanation of Solution

In the depiction three chlorine atoms are connected with central atom phosphorus. Hence the molecular formula of the molecules is ${\text{PCl}}_{\text{3}}$ .

Molecular mass of ${\text{PCl}}_{\text{3}}$ is calculated as follows:

  $\begin{array}{c}\text{Molecular}\text{mass}\text{of}{\text{PCl}}_{\text{3}}=\left(\begin{array}{l}\left(1\right)\left(\text{Atomic}\text{mass}\text{of}\text{P}\right)\text{+}\\ \left(3\right)\left(\text{Atomic}\text{mass}\text{of}\text{Cl}\right)\end{array}\right)\\ =\left[\left(\text{1}\right)\left(30.97\text{ amu}\right)+\left(3\right)\left(35.45\text{ amu}\right)\right]\\ =30.97\text{ amu}+106.35\text{ amu}\\ =137.32\text{ amu}\end{array}$

Name of the compound ${\text{PCl}}_{\text{3}}$ is phosphorus trichloride.

d)

Interpretation Introduction

Interpretation: Molecular mass of the below-mentioned depiction is to be given. Also, correct name of compound should be done if it is named incorrectly.

  

Concept introduction:In the molecular formula, the exact number and type of constituent atoms are shown. Type of constituent atoms is represented by their atomic symbols and number of each constituent atom is represented in the right subscript of its atomic symbol. In a hypothetical molecule ${\text{A}}_{\text{x}}{\text{B}}_{\text{y}}$ , x number of $\text{A}$ atom and y number of $\text{B}$ atom combines to form the compound.

Formula to calculate molecular mass of ${\text{A}}_{\text{x}}{\text{B}}_{\text{y}}$ is as follows:

  $\text{Molecular}\text{mass}\text{of}{\text{A}}_{\text{x}}{\text{B}}_{\text{y}}\text{=}\left(\begin{array}{l}\left(\text{x}\right)\left(\text{Atomic}\text{mass}\text{of}\text{A}\right)\text{+}\\ \left(\text{y}\right)\left(\text{Atomic}\text{mass}\text{of}\text{B}\right)\end{array}\right)$

Explanation of Solution

In the depiction two oxygen atoms are connected central nitrogen atom that forms ${\text{NO}}_{\text{2}}$ group and two ${\text{NO}}_{\text{2}}$ groups are linked with one oxygen atom. Hence the molecular formula of the molecules is ${\text{N}}_{\text{2}}{\text{O}}_{\text{5}}$ .

Molecular mass of ${\text{N}}_{\text{2}}{\text{O}}_{\text{5}}$ is calculated as follows:

  $\begin{array}{c}\text{Molecular}\text{mass}\text{of}{\text{N}}_{\text{2}}{\text{O}}_{\text{5}}=\left(\begin{array}{l}\left(2\right)\left(\text{Atomic}\text{mass}\text{of}\text{N}\right)+\\ \left(5\right)\left(\text{Atomic}\text{mass}\text{of}\text{O}\right)\end{array}\right)\\ =\left[\left(\text{2}\right)\left(14.01\text{ amu}\right)+\left(5\right)\left(16\text{ amu}\right)\right]\\ =28.02\text{ amu}+80\text{ amu}\\ =108.02\text{ amu}\end{array}$

Name of the compound ${\text{N}}_{\text{2}}{\text{O}}_{\text{5}}$ is dinitrogenpentoxide.