How many moles of electrons weigh one kilogram?

Options

A. `6.023 xx 10^(23)`
B. `1/(9.108) xx 10^(21)`
C. `(6.023)/(6.018) xx 10^(54)`
D. `1/(9.108 xx 6.023)xx 10^(8)`

Answer

D

Explanation

Mass of an electron `=9.108 xx 10^(-31)` kg
Mass of 1 mol of electrons `=9.108 xx 10^(-31) xx 6.023 xx 10^(23) = 9.108 xx 6.023 xx 10^(-8)` kg
No. of moles in 1 kg `=1/(9.108 xx 10^(-8) xx 6.023 xx 10^(23))`