Question

(i) Calculate the number of electrons which will together with one gram .
(ii) Calculate the mass and charge on one mole of electrons .

Answer 1

(i) Mass of an electron `=9.1 xx 10^(-28) g`
`9.1 xx 10^(-28) g` is the mass of = 1 electron
1.0 g is the mass of `=(1)/(9.1 xx 10^(-28))=1.098 xx 10^(27)` electrons
(ii) One mole of electrons `=6.022 xx 10^(23) `electrons
Mass of 1 electron `=9.1 xx 10^(-31) kg`
Mass of `6.022 xx 10^(23)` electrons `=(9.1 xx 10^(-31)kg) xx (6.022 xx 10^(23))=5.48 xx 10^(-7)kg`
Charge on one electron =`1.602 xx 10^(-19) ` couldomb
Charge on one mole electrons `=1.602 xx 10^(-19) xx 6.022 xx 10^(23) = 9.65 xx 10^(4)` coulombs