Chapter 3, Problem 1E

What is the total mass (amu) of carbon in each of the following molecules?

1. ${\text{CH}}_4$
2. ${\text{CHCl}}_3$
3. ${\text{C}}_{12}{\text{H}}_{12}{\text{O}}_6$
4. ${\text{CH}}_3{\text{CH}}_2{\text{CH}}_2{\text{CH}}_2{\text{CH}}_3$

Interpretation Introduction

Interpretation:

The total mass (amu) of carbon in ${\text{CH}}_{\text{4}}$ should be determined.

Concept Introduction:

The mass unit which is used to denote molecular and atomic weights, equal to one twelfth of the mass of an atom of carbon-12 is known as atomic mass unit.

  $\text{1 amu = mass of C-12×}\frac{\text{1}}{\text{12}}$

Answer to Problem 1E

The total mass (amu) of carbon in ${\text{CH}}_{\text{4}}$ is $12.01\text{ amu}$

Explanation of Solution

In ${\text{CH}}_{\text{4}}$ , there is only 1 carbon atom and atomic mass of one carbon atom is equal to 12.01 amu.

Thus, the total mass (amu) of carbon in ${\text{CH}}_{\text{4}}$ is $12.01\text{ amu}$

Interpretation Introduction

Interpretation:

The total mass (amu) of carbon in ${\text{CHCl}}_{\text{3}}$ should be determined

Concept Introduction:

The mass unit which is used to denote molecular and atomic weights, equal to one twelfth of the mass of an atom of carbon-12 is known as atomic mass unit.

  $\text{1 amu = mass of C-12×}\frac{\text{1}}{\text{12}}$

Answer to Problem 1E

The total mass (amu) of carbon in ${\text{CHCl}}_{\text{3}}$ is $12.0\text{1 amu}$

Explanation of Solution

In ${\text{CHCl}}_{\text{3}}$ , there is only 1 carbon atom and atomic mass of one carbon atom is equal to 12.01 amu.

Thus, the total mass (amu) of carbon in ${\text{CHCl}}_{\text{3}}$ is $12.01\text{ amu}$

Interpretation Introduction

Interpretation:

The total mass (amu) of carbon in ${\text{C}}_{\text{12}}{\text{H}}_{\text{10}}{\text{O}}_{\text{6}}$ should be determined

Concept Introduction:

The mass unit which is used to denote molecular and atomic weights, equal to one twelfth of the mass of an atom of carbon-12 is known as atomic mass unit.

  $\text{1 amu = mass of C-12×}\frac{\text{1}}{\text{12}}$

Answer to Problem 1E

The total mass (amu) of carbon in ${\text{C}}_{\text{12}}{\text{H}}_{\text{10}}{\text{O}}_{\text{6}}$ is $144.12\text{ amu}$

Explanation of Solution

In ${\text{C}}_{\text{12}}{\text{H}}_{\text{10}}{\text{O}}_{\text{6}}$ , there are 12 carbon atoms and atomic mass of one carbon atom is equal to 12.01 amu.

Thus, the total mass (amu) of carbon in ${\text{C}}_{\text{12}}{\text{H}}_{\text{10}}{\text{O}}_{\text{6}}$ is calculated as follows:

  $12\times 12.01\text{ amu}=144.12\text{ amu}$

Interpretation Introduction

Interpretation:

The total mass (amu) of carbon in ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{3}}$ should be determined.

Concept Introduction:

The mass unit which is used to denote molecular and atomic weights, equal to one twelfth of the mass of an atom of carbon-12 is known as atomic mass unit.

  $\text{1 amu = mass of C-12×}\frac{\text{1}}{\text{12}}$

Answer to Problem 1E

The total mass (amu) of carbon in ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{3}}$ is $60.05\text{ amu}$

Explanation of Solution

In ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{3}}$ , there are 5 carbon atoms and atomic mass of one carbon atom is equal to 12.01 amu.

Thus, the total mass (amu) of carbon in ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{3}}$ is calculated as follows:

  $5\times 12.01\text{ amu}=60.05\text{ amu}$