Chapter 10, Problem 108A

Calculate the mass of each element.

a. 5.22 mol of He

b. 0.0455 mol of Ni

c. 2.22 mol of Ti

d. 0.00566 mol of Ge

Interpretation Introduction

(a)

Interpretation:

The mass of 5.22 mole of He should be calculated.

Concept introduction:

Number of moles of a compound is defined as the ratio of given mass of the compound to the molar or molecular mass of the compound.

The mathematical expression is given by:

Number of moles = $\frac{\text{mass of the compound}}{\text{molar mass of the compound}}$

The one mole of any substance is equal to the Avogadro number i.e. $6.022\times {10}^{23}$ atoms.

Answer to Problem 108A

Mass of 5.22 mole of helium = 20.88 g.

Explanation of Solution

The mathematical expression for the calculation of number of moles is given by:

Number of moles = $\frac{\text{mass of the compound}}{\text{molar mass of the compound}}$

The above expression is rearranged as:

$\text{Mass = Number of moles×molar mass}$

Molar mass of Helium = 4 g/mole

Number of moles of helium = 5.22 mole

Put the values,

$\text{Mass = Number of moles×molar mass of the compound}$

$\begin{array}{l}\text{Mass of helium = 5}\text{.22 mole ×4 g/mole}\\ \text{ = 20}\text{.88 g}\end{array}$

Interpretation Introduction

(b)

Interpretation:

The mass of 0.0455 mole of Ni should be calculated.

Concept introduction:

Number of moles of a compound is defined as the ratio of given mass of the compound to the molar or molecular mass of the compound.

The mathematical expression is given by:

Number of moles = $\frac{\text{mass of the compound}}{\text{molar mass of the compound}}$

The one mole of any substance is equal to the Avogadro number i.e. $6.022\times {10}^{23}$ atoms.

Answer to Problem 108A

Mass of 0.0455 mole of Ni = $\text{2}\text{.67 g}$.

Explanation of Solution

The mathematical expression for the calculation of number of moles is given by:

Number of moles = $\frac{\text{mass of the compound}}{\text{molar mass of the compound}}$

The above expression is rearranged as:

$\text{Mass = Number of moles×molar mass}$

Molar mass of nickel = 58.69 g/mole

Number of moles of nickel = 0.0455 mole

Put the values,

$\text{Mass = Number of moles×molar mass of the compound}$

$\begin{array}{l}\text{Mass of nickel = 0}\text{.0455 mole ×58}\text{.69 g/mole}\\ \text{ = 2}\text{.67 g}\end{array}$

Interpretation Introduction

(c)

Interpretation:

The mass of 2.22 mole of Ti should be calculated.

Concept introduction:

Number of moles of a compound is defined as the ratio of given mass of the compound to the molar or molecular mass of the compound.

The mathematical expression is given by:

Number of moles = $\frac{\text{mass of the compound}}{\text{molar mass of the compound}}$

The one mole of any substance is equal to the Avogadro number i.e. $6.022\times {10}^{23}$ atoms.

Answer to Problem 108A

Mass of 2.22 mole of Ti = $\text{106}\text{.26 g}$.

Explanation of Solution

The mathematical expression for the calculation of number of moles is given by:

Number of moles = $\frac{\text{mass of the compound}}{\text{molar mass of the compound}}$

The above expression is rearranged as:

$\text{Mass = Number of moles×molar mass}$

Molar mass of titanium = 47.867 g/mole

Number of moles of titanium = 2.22 mole

Put the values,

$\text{Mass = Number of moles×molar mass of the compound}$

$\begin{array}{l}\text{Mass of titanium = 2}\text{.22 mole ×47}\text{.867 g/mole}\\ \text{ = 106}\text{.26 g}\end{array}$

Interpretation Introduction

(d)

Interpretation:

The mass of 0.00566 mole of $\text{Ge}$ should be calculated.

Concept introduction:

Number of moles of a compound is defined as the ratio of given mass of the compound to the molar or molecular mass of the compound.

The mathematical expression is given by:

Number of moles = $\frac{\text{mass of the compound}}{\text{molar mass of the compound}}$

The one mole of any substance is equal to the Avogadro number i.e. $6.022\times {10}^{23}$ atoms.

Answer to Problem 108A

Mass of 0.00566 mole of $\text{Ge}$ = $\text{0}\text{.411 g}$.

Explanation of Solution

The mathematical expression for the calculation of number of moles is given by:

Number of moles = $\frac{\text{mass of the compound}}{\text{molar mass of the compound}}$

The above expression is rearranged as:

$\text{Mass = Number of moles×molar mass}$

Molar mass of germanium = 72.64 g/mole

Number of moles of germanium = 0.00566 mole

Put the values,

$\text{Mass = Number of moles×molar mass of the compound}$

$\begin{array}{l}\text{Mass of germanium = 0}\text{.00566 mole ×72}\text{.64 g/mole}\\ \text{ = 0}\text{.411 g}\end{array}$