Question

The value of the Avogadro constant is:
A. \[6.022 \times {10^{24}}\]
B. $6.022 \times {10^{22}}$
C. $60.22 \times {10^{24}}$
D. $6.022 \times {10^{23}}$

Answer 1

Hint: The Avogadro constant is the proportionality factor that relates the number of constituent particles in a sample with the amount of substance in that sample. Its SI unit is the reciprocal of mole. It is represented as ${N_A}$.

Complete Step by step answer:
The number of units in one mole of substance is known as Avogadro’s constant or Avogadro number. Basically, the units may be ions, electrons, atoms or molecules based on the character of the reaction and the type of the product.
However, the value of Avogadro’s number is fixed i.e. $6.022 \times {10^{23}}$
One of the famous French physicists Jean Baptiste Perrin used the term Avogadro’s number for the first time while explaining Brownian motion. Afterwards, the value of Avogadro’s number was obtained by dividing the charge of a mole of electrons by the charge of a single electron which is equal to $6.02214154 \times {10^{23}}$particles per mole.
Further, in the field of chemistry, a mole is defined as the amount of a substance that contains exactly $6.022 \times {10^{23}}$elementary entities of the given substance. The number of moles of a substance in a given pure sample can be represented by the following formula:
$n = \dfrac{N}{{{N_A}}}$
Where, n is the number of moles of the substance
N is the total number of elementary entities in the sample and ${N_A}$is the Avogadro constant.

Hence, option D is correct.

Note: The word “mole” was introduced in the year 1896 by the German chemist Wilhelm Ostwald, who derived the term from the Latin word moles meaning heap or pile However, the number of moles of a molecule may not always be equal to the number of moles of its constituent elements.