Chapter 10, Problem 116A

Interpretation Introduction

Interpretation:

The number of atoms of sulfur and vanadium present in the compound 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 116A

Number of atoms of $\text{S}$ = $7.25\times {10}^{22}\text{ atoms}$

Number of atoms of $\text{V}$ = $4.82\times {10}^{22}\text{ atoms}$

Explanation of Solution

Mass of sulfur = 3.86 g

Mass of vanadium = 4.08 g

Molar mass of sulfur = 32.065 g/mole

$\text{Number of moles of sulfur = }\frac{\text{3}\text{.86 g}}{32.065\text{ g/mole}}$

Number of moles of $\text{S}$ = $\text{0}\text{.12038 mole}$

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,

$\text{0}\text{.12038 mole}$ = $\text{Number of atoms ×}\frac{1\text{ mole}}{6.022\times 10\text{atoms}}$

$\text{Number of atoms }=\text{0}\text{.12038 mole}\times 6.022\times {10}^{23}\frac{\text{atoms}}{\text{mole}}$

Number of atoms of $\text{S}$ = $7.25\times {10}^{22}\text{ atoms}$

Molar mass of vanadium = 50.94 g/mole

$\text{Number of moles of vanadium = }\frac{\text{4}\text{.08 g}}{50.94\text{ g/mole}}$

Number of moles of $\text{V}$ = $\text{0}\text{.0800 mole}$

Put the values,

$\text{0}\text{.0800 mole}$ = $\text{Number of atoms ×}\frac{1\text{ mole}}{6.022\times 10\text{atoms}}$

$\text{Number of atoms }=\text{0}\text{.0800 mole}\times 6.022\times {10}^{23}\frac{\text{atoms}}{\text{mole}}$

Number of atoms of $\text{V}$ = $4.82\times {10}^{22}\text{ atoms}$