Question

The mass of 1 mole of electron is:

• A. 0.55 mg
• B. $9.1\times {10}^{-28}g$
• C. $9.1\times {10}^{-27}g$
• D. 1.008 mg

Answer 1

The correct option is A 0.55 mg

1 electron weighs approximately $9.11\times {10}^{-31}$ Kg
1 mol weighs $X$ Kg
1 mol is$6.022\times {10}^{23}$ particles
So we put $6.022\times {10}^{23}$ in the equation instead.
$X=\frac{9.11\times {10}^{-31}}{1\times 6.022\times {10}^{23}}=5.48\times {10}^{-7}$ Kg

$\therefore$ mass of one electron $=0.548mg\approx 0.55mg$