Chapter 10, Problem 88A

Interpretation Introduction

Interpretation:

Use of Avogadro’s number as a conversion factor needs to be explained.

Concept introduction:

In 1 mol of any substance, there are $6.022\times {10}^{23}$ units of that substance. These units can be atoms and molecules. The number of units in 1 mol of any substance is known as Avogadro’s number. It is denoted by symbol N_A.

Explanation of Solution

The unit of amount in chemistry is known as mole. It helps in determining the atoms and mass of the material. There are $6.022\times {10}^{23}$ units in 1 mol of a substance. The representative particles depend on the type of the substance. For example, for a compound, the representative particles are molecules and it is atoms in the case of elements.

Thus, the mathematical relation between Avogadro’s number and moles can be represented as follows:

$N=n{N}_A$

Here, N is number of representative particles, n is number of moles and N_A is Avogadro’s number.

Or,

$N=n\left(6.022\times {10}^{23}\right)$

For 1 mol,

$N=6.022\times {10}^{23}$

Therefore, to calculate the number of representative particles, the Avogadro’s number is used to multiply with the number of moles of the given substance.

The conversion factor will be:

$\frac{6.022\times {10}^{23}}{\text{ 1 mol}}$