Question

The mass of $ 1 $ mole of electrons is :

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

Answer 1

Answer: (C)

One mole of electrons $= 6.023 × 10^{23}$ electrons
Mass of one electron $ = 9.1 × 10^{-28} \, g$
Mass of one mole of electrons
$= 6.032×10^{23} × 9.1 × 10^{-28}\,g$
$= 5.48 × 10^{-4} \, g = 0.548 \,mg ≈ 0. 55 \,mg$