Question

How many moles of electron weight one kilogram?

• A. $6.023\times {10}^{23}$
• B. $\frac{1}{9.108}\times {10}^{31}$
• 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.

1 mole of electrons $=6.023\times {10}^{23}$ electrons.

Mass of 1 mole of electrons $=9.108\times {10}^{-31}\times 6.023\times {10}^{23}=9.108\times 6.023\times {10}^{-8}$ kg.

$\frac{1}{9.108\times 6.023\times {10}^{-8}}=\frac{1}{9.108\times 6.023}\times {10}^8$ electrons will weigh 1 kg.