Question

How many moles of electron weighs one kilogram?

• A. $6.023\times {10}^{23}$
• B. $\frac{1}{9.108}\times {10}^{32}$
• C. $\frac{6.023}{9.108}\times {10}^{54}$
• D. $\frac{1}{9.108\times 6.023}\times {10}^8$

Answer 1

Answer: (D)

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

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

Mass of one mole of electrons $=9.108\times {10}^{-31}\times 6.023\times {10}^{23}=9.108\times 6.023\times {10}^{-8}$ kg.

The number of moles of electrons that weigh one kilogram $=\frac{1}{9.108\times 6.023\times {10}^{-8}}=\frac{1}{9.108\times 6.023}\times {10}^8$

Hence, the correct option is $D$