Chapter 8, Problem 15E

Interpretation Introduction

(a)

Interpretation:

The molar mass of calcium sulfide $\text{CaS}$ is to be stated.

Concept introduction:

The mass of one mole of any substance is known as its molar mass. The molar mass of an element is equal to the atomic mass of an element. Molar mass is expressed in $\text{g}/\text{mol}$. The molar mass of a compound is the sum of all the atoms of each element present in the compound.

Answer to Problem 15E

The molar mass of calcium sulfide $\text{CaS}$ is $72.143\text{g}/\text{mol}$.

Explanation of Solution

The molar mass of calcium sulfide $\text{CaS}$ is computed by the formula written below.

$\text{Molar mass of calcium sulfide}=\text{Molar mass of calcium}+\text{Molar mass of sulfur}$  …(1)

The value of molar mass of calcium and sulfur are $\text{40}\text{.078 }\text{g}/\text{mol}$ and $\text{32}\text{.065 }\text{g}/\text{mol}$ respectively.

Substitute the values of molar mass of calcium and sulfur in equation number (1).

$\begin{array}{rll}\text{Molar mass of calcium sulfide}& =& \text{Molar mass of calcium}+\text{Molar mass of sulfur}\\ & =& \text{40}\text{.078 }\text{g}/\text{mol}+\text{32}\text{.065 }\text{g}/\text{mol}\\ & =& \text{72}\text{.143 }\text{g}/\text{mol}\end{array}$

Therefore, the molar mass of the calcium sulfide $\text{CaS}$ is $72.143\text{g}/\text{mol}$.

Conclusion

The molar mass of the calcium sulfide $\text{CaS}$ is $72.143\text{g}/\text{mol}$.

Interpretation Introduction

(b)

Interpretation:

The molar mass of the calcium sulfate, ${\text{CaSO}}_{\text{4}}$ is to be stated.

Concept introduction:

The mass of one mole of any substance is known as its molar mass. The molar mass of an element is equal to the atomic mass of an element. Molar mass is expressed in $\text{g}/\text{mol}$. The molar mass of a compound is the sum of all the atoms of each element present in the compound.

Answer to Problem 15E

The molar mass of calcium sulfate, ${\text{CaSO}}_{\text{4}}$ is $\text{136}\text{.143}\text{ g}/\text{mol}$.

Explanation of Solution

The molar mass of calcium sulfate, ${\text{CaSO}}_{\text{4}}$ is computed by the formula written below.

$\text{Molar mass of calcium sulfate}=\left(\begin{array}{l}\text{Molar mass of calcium}+\text{Molar mass of sulfur}+\\ 4\times \text{molar mass of oxygen}\end{array}\right)$ …(2)

The value of molar mass of calcium, sulfur and oxygen are $\text{40}\text{.078 }\text{g}/\text{mol}$, $\text{32}\text{.065 }\text{g}/\text{mol}$ and $\text{16}\text{.00 }\text{g}/\text{mol}$ respectively.

Substitute the values of molar mass of calcium, sulfur and oxygen in equation number (2).

$\begin{array}{rll}\text{Molar mass of calcium sulfate}& =& \left(\begin{array}{l}\text{Molar mass of calcium}+\text{Molar mass of sulfur}+\\ \text{4}\times \text{molar mass of oxygen}\end{array}\right)\\ & =& \text{40}\text{.078 }\text{g}/\text{mol}+\text{32}\text{.065 }\text{g}/\text{mol}+\text{4}\times \text{16}\text{.00 }\text{g}/\text{mol}\\ & =& \text{136}\text{.143 }\text{g}/\text{mol}\end{array}$

Therefore, the molar mass of calcium sulfate ${\text{CaSO}}_{\text{4}}$ is $136.143\text{g}/\text{mol}$.

Conclusion

The molar mass of calcium sulfate, ${\text{CaSO}}_{\text{4}}$ is $\text{136}\text{.143}\text{ g}/\text{mol}$.

Interpretation Introduction

(c)

Interpretation:

The molar mass of dichlorine pentaoxide, ${\text{Cl}}_{\text{2}}{\text{O}}_{\text{5}}$ is to be stated.

Concept introduction:

The mass of one mole of any substance is known as its molar mass. The molar mass of an element is equal to the atomic mass of an element. Molar mass is expressed in $\text{g}/\text{mol}$. The molar mass of a compound is the sum of the all the atoms of each element present in the compound.

Answer to Problem 15E

The molar mass of dichlorine pentaoxide, ${\text{Cl}}_{\text{2}}{\text{O}}_{\text{5}}$ is $\text{150}\text{.906 }\text{g}/\text{mol}$.

Explanation of Solution

The molar mass of dichlorine pentaoxide, ${\text{Cl}}_{\text{2}}{\text{O}}_{\text{5}}$ is computed by the formula written below.

$\text{Molar}\text{mass}\text{of}\text{dichlorine}\text{pentaoxide}=\left(\begin{array}{c}\text{2}\times \text{molar mass of chlorine}+\\ \text{5}\times \text{molar mass of oxygen}\end{array}\right)$  …(3)

The value of molar mass of chlorine and oxygen is $\text{35}\text{.453 }\text{g}/\text{mol}$ and $\text{16}\text{.00 }\text{g}/\text{mol}$ respectively.

Substitute the values of molar mass of chlorine and oxygen in the equation number (3).

$\begin{array}{rll}\text{Molar}\text{mass}\text{of}\text{dichlorine}\text{pentaoxide}& =& \left(\begin{array}{c}\text{2}\times \text{molar mass of chlorine}+\\ \text{5}\times \text{molar mass of oxygen}\end{array}\right)\\ & =& \text{2}\times \text{35}\text{.453 }\text{g}/\text{mol}+\text{5}\times \text{16}\text{.00 }\text{g}/\text{mol}\\ & =& \text{150}\text{.906 }\text{g}/\text{mol}\end{array}$

Therefore the molar mass of dichlorine pentaoxide, ${\text{Cl}}_{\text{2}}{\text{O}}_{\text{5}}$ is $\text{150}\text{.906 }\text{g}/\text{mol}$.

Conclusion

The molar mass of dichlorine pentaoxide, ${\text{Cl}}_{\text{2}}{\text{O}}_{\text{5}}$ is $\text{150}\text{.906 }\text{g}/\text{mol}$.

Interpretation Introduction

(d)

Interpretation:

The molar mass of glycerin, ${\text{C}}_{\text{3}}{\text{H}}_{\text{5}}{\left(\text{OH}\right)}_{\text{3}}$ is to be stated.

Concept introduction:

The mass of one mole of any substance is known as its molar mass. The molar mass of an element is equal to the atomic mass of an element. Molar mass is expressed in $\text{g}/\text{mol}$. The molar mass of a compound is the sum of all the atoms of each element present in the compound.

Answer to Problem 15E

The molar mass of glycerin, ${\text{C}}_{\text{3}}{\text{H}}_{\text{5}}{\left(\text{OH}\right)}_{\text{3}}$ is $\text{92}\text{.00 }\text{g}/\text{mol}$.

Explanation of Solution

The molar mass of glycerin, ${\text{C}}_{\text{3}}{\text{H}}_{\text{5}}{\left(\text{OH}\right)}_{\text{3}}$ is computed by the formula written below.

$\text{Molar mass of glycerin}=\left(\begin{array}{c}\text{3}\times \text{molar mass of carbon}+\\ \text{3}\times \text{molar mass of oxygen}+\\ \text{8}\times \text{molar mass of hydrogen}\end{array}\right)$  …(4)

The value of molar mass of carbon, oxygen and hydrogen are $\text{12}\text{.01 }\text{g}/\text{mol}$, $\text{16}\text{.00 }\text{g}/\text{mol}$ and $\text{1}\text{.01 }\text{g}/\text{mol}$ respectively.

Substitute the values of molar mass of carbon, oxygen and hydrogen in equation (4).

$\begin{array}{rll}\text{Molar mass of glycerin}& =& \left(\begin{array}{c}\text{3}\times \text{molar mass of carbon}+\\ \text{3}\times \text{molar mass of oxygen}+\\ \text{8}\times \text{molar mass of hydrogen}\end{array}\right)\\ & =& \text{3×12}\text{.01 }\text{g}/\text{mol}+\text{3}\times \text{16}\text{.00 }\text{g}/\text{mol}+\text{8}\times \text{1}\text{.01 }\text{g}/\text{mol}\\ & =& \text{92}\text{.11 }\text{g}/\text{mol}\end{array}$

Conclusion

The molar mass of glycerin, ${\text{C}}_{\text{3}}{\text{H}}_{\text{5}}{\left(\text{OH}\right)}_{\text{3}}$ is $\text{92}\text{.11 }\text{g}/\text{mol}$.