Question

How many moles of electrons weighs 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)

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

$\because 9.108\times {10}^{-31}$ kg of electrons contain$\frac{1}{6.023\times {10}^{23}}mol$.
$\therefore 1kg$ of electron will contain$\frac{1}{6.023\times {10}^{23}\times 9.108\times {10}^{-31}}$ $=\frac{1}{6.023\times 9.108}\times {10}^{8}mol$.

Hence, the correct option is $D$