Question

The mass of half mole of electron is about? (given mass of electron = 9.109 × 10^ - 28) plss solve this and the answer should be 0.274mg

Answer 1

Bonjour!

To find:- Mass of half mole of electron.

1 mole of electron contains 6.022 × 10²³ electrons.

So, 1/2 mole of electron will contain 3.011 × 10²³ electrons.

Mass of one electron is = 9.109 × 10^-28 g

So, mass of 3.011 × 10-²³ electrons will be

$= 3.011 \times {10}^{ 23} \times 9.101 \times {10}^{ - 28} \: g \\ \\ = 27.4 \times {10}^{ - 5} \: g \\ \\ = 27.4 \times {10}^{ - 5} \times {10}^{3} \: mg \\ \\ = 27.4 \times {10}^{ - 2} \: mg \\ \\ = 0.274 \: mg$


Therefore mass of 1/2 mole of electron is = 0.274 mg

Hope this helps...:)

Answer 2

Answer :-

→ 0.264 mg.

Step-by-step explanation :-

One electron weighs 9.109 x 10⁻²⁸ g.

→ 1 mole has 6.022 x 10²³ electrons.

Therefore, Mass of 1 mole of electron

=9.1 x 10⁻²⁸ x 6.022x 10²³.

=54.8 x 10⁻⁵ g.

Thus, Half mole of electron = ( 54.8 x 10⁻⁵)/2.

=27.4 x10⁻⁵ g.

=0.274 mg.

Hence, it is solved.