Question

How many moles of electron weight one kilogram :

• A. $6.023\times 10^{23}$
• B. $\frac{1}{9.108}\times 10^{23}$
• C. $\frac{6.023}{9.108}\times 10^{54}$
• D. $\frac{1}{9.108\times 6.023}\times 10^8$

Answer 1

Answer: (D)

Mass of an electron $=9.108\times 10^{-31}kg$

Mass of one mole of electron

$=\left(9.108\times 10^{-31}\times 6.023\times 10^{23}\right)kg$

Then, number of mole of electron in $1kg$

$=\frac{1}{9.108\times 6.023\times 10^{-8}}$

$=\frac{1}{9.08\times 6.023}\times 10^8$ mole of $e^{-}$