Chapter 10, Problem 105A

Interpretation Introduction

Interpretation:

The conversion from number of atoms of a specific element to its mass should be explained.

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.

Explanation of Solution

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

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

Thus, first step is to convert the number of molecules/atoms into number of moles with the help of above formula. After that, multiply the number of moles with molar mass of the element to obtain the mass of the given element.

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

$\mathrm{molar}mass\times numberofmoles=mass$