Question

The mass of 1 mole electron is 0.55mg
(A)True
(B) False

Answer 1

Hint: We know that the mass of an electron is $9.1\times 10^{-31}\mathrm{k}\mathrm{g}$. 1 mole of electron is equal to the Avogadro constant that is$6.022\times {10}^{23}$electrons. Avogadro’s constant is written as ${\mathrm{N}}_{\mathrm{A}}$

Complete step by step answer:
We know that,
The mass of $1$ electron $=9.1\times 10^{-31}\mathrm{k}\mathrm{g}$which is equivalent to $9.1\times 10^{-25}\mathrm{m}\mathrm{g}$
1mole of electron = $6.02\times 10^{23}\mathrm{e}\mathrm{l}\mathrm{e}\mathrm{c}\mathrm{t}\mathrm{r}\mathrm{o}\mathrm{n}\mathrm{s}$
For getting the mass of $1$ mole of electrons we must multiply the mass of an electron with $1$ mole of electrons
i.e. Mass of 1 mole of electrons $=$ mass of $1$ electron $\times$number of one mole of electron
$=$$\left(9.1\times 10^{-25}\right)\times \left(6.02\times 10^{23}\right)$
$=$$0.54782\mathrm{m}\mathrm{g}$
$\approx 0.55\mathrm{m}\mathrm{g}$
$\therefore$The mass of one mole of electrons $=0.55\mathrm{m}\mathrm{g}$
Therefore, the mass of $1$ mole of electrons is $0.55\mathrm{m}\mathrm{g}$ this statement is true.

Additional Information:
Mole is a unit to represent the quantity of substance.$1$ mole of any substance contains $6.022\times 10^{23}$ particles and this number is known as Avogadro Number $\left({\mathrm{N}}_{\mathrm{A}}\right)$.
$1\mathrm{m}\mathrm{o}\mathrm{l}=6.022\times 10^{23}$ particles
For finding the number of moles we use the above formula, that is, given mass divided by molar mass. If there is a given number of particles, then we will use the formula given number of particles divided by Avogadro number.
Gram molecular volume: Same volume is occupied by one-gram molecule of any of the dry gas at standard temperature and pressure i.e. $22.4\mathrm{L}$ This is termed as gram molecular volume.
Relationship between mole, GMV and Avogadro number can be given as,
1 gram of molecule of any dry gas occupies $22.4\mathrm{L}$ volume at STP. Hence at STP$22.4\mathrm{L}$ of dry gas is equivalent to one mole of that gas and it contains $6.022\times 10^{23}$molecules i.e. Avogadro number of molecules.

Note:
A mole is the chemist's counting unit. We know that carbon 12 has a significant role in terms of the Avogadro’s constants. The Avogadro constant $6.022\times {10}^{23}$ is defined as the number of atoms in exactly $12\mathrm{g}$ of carbon $12$.