Chapter 10, Problem 113A

Interpretation Introduction

(a)

Interpretation:

The number of atoms of 25.8 g of Hg 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 = $\frac{\text{given mass of the compound}}{\text{molar mass of the compound}}$

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

Answer to Problem 113A

Number of atoms of $\text{Hg}$ = $7.768\times {10}^{22}\text{ atoms}$

Explanation of Solution

Mass of $\text{Hg}$ = 25.8 g

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

Molar mass of $\text{Hg}$ = 200.59 g/mole

Put the values,

$\text{Number of moles = }\frac{\text{25}\text{.8 g}}{200.59\text{ g/mole}}$

Number of moles of $\text{Hg}$ = $\text{0}\text{.129 mole}$

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

Number of moles = $\text{number of atoms ×}\frac{1\text{ mole}}{6.022\times 10\text{atoms}}$

Put the values,

$\text{0}\text{.129 mole}$ = $\text{Number of atoms ×}\frac{1\text{ mole}}{6.022\times 10\text{atoms}}$

$\text{Number of atoms }=0.129\text{ mole}\times 6.022\times {10}^{23}\frac{\text{atoms}}{\text{mole}}$

Number of atoms of $\text{Hg}$ = $7.768\times {10}^{22}\text{ atoms}$

Interpretation Introduction

(b)

Interpretation:

The number of atoms of 0.0340 g of Zn should be calculated.

Concept introduction:

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

The mathematical expression is given by:

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

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

Answer to Problem 113A

Number of atoms of $\text{Zn}$ = $3.130\times {10}^{20}\text{ atoms}$

Explanation of Solution

Mass of $\text{Zn}$ = 0.0340 g

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

Molar mass of $\text{Zn}$ = 65.39 g/mole

Put the values,

$\text{Number of moles = }\frac{\text{0}\text{.0340 g}}{65.39\text{ g/mole}}$

Number of moles of $\text{Zn}$ = $5.199\times {10}^{-4}\text{ mole}$

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

Number of moles = $\text{number of atoms ×}\frac{1\text{ mole}}{6.022\times 10\text{atoms}}$

Put the values,

$5.199\times {10}^{-4}\text{ mole}$ = $\text{Number of atoms ×}\frac{1\text{ mole}}{6.022\times 10\text{atoms}}$

$\text{Number of atoms }=5.199\times {10}^{-4}\text{ mole}\times 6.022\times {10}^{23}\frac{\text{atoms}}{\text{mole}}$

Number of atoms of $\text{Zn}$ = $3.130\times {10}^{20}\text{ atoms}$

Interpretation Introduction

(c)

Interpretation:

The number of atoms of 150 g of $\text{Ar}$ 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 = $\frac{\text{given mass of the compound}}{\text{molar mass of the compound}}$

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

Answer to Problem 113A

Number of atoms of $\text{Ar}$ = $2.26\times {10}^{24}\text{ atoms}$

Explanation of Solution

Mass of $\text{Ar}$ = 150 g

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

Molar mass of $\text{Ar}$ = 39.948 g/mole

Put the values,

$\text{Number of moles = }\frac{\text{150 g}}{39.948\text{ g/mole}}$

Number of moles of $\text{Ar}$ = $3.755\text{ mole}$

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

Number of moles = $\text{number of atoms ×}\frac{1\text{ mole}}{6.022\times 10\text{atoms}}$

Put the values,

$3.755\text{ mole}$ = $\text{Number of atoms ×}\frac{1\text{ mole}}{6.022\times 10\text{atoms}}$

$\text{Number of atoms }=3.755\text{ mole}\times 6.022\times {10}^{23}\frac{\text{atoms}}{\text{mole}}$

Number of atoms of $\text{Ar}$ = $2.26\times {10}^{24}\text{ atoms}$

Interpretation Introduction

(d)

Interpretation:

The number of atoms of 0.124 g of $\text{Mg}$ should be calculated.

Concept introduction:

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

The mathematical expression is given by:

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

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

Answer to Problem 113A

Number of atoms of $\text{Mg}$ = $3.071\times {10}^{21}\text{ atoms}$

Explanation of Solution

Mass of $\text{Mg}$ = 0.124 g

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

Molar mass of $\text{Mg}$ = 24.305 g/mole

Put the values,

$\text{Number of moles = }\frac{\text{0}\text{.124 g}}{24.305\text{ g/mole}}$

Number of moles of $\text{Mg}$ = $0.0051\text{ mole}$

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

Number of moles = $\text{number of atoms ×}\frac{1\text{ mole}}{6.022\times 10\text{atoms}}$

Put the values,

$0.0051\text{ mole}$ = $\text{Number of atoms ×}\frac{1\text{ mole}}{6.022\times 10\text{atoms}}$

$\text{Number of atoms }=0.0051\text{ mole}\times 6.022\times {10}^{23}\frac{\text{atoms}}{\text{mole}}$

Number of atoms of $\text{Mg}$ = $3.071\times {10}^{21}\text{ atoms}$