Question

The total number of electrons present in 20 mL of water is ____________.

(Density = 1 g mL⁻¹)

Options

• 6.684 × 10²⁴

• 6.022 × 10²⁴

• 4.684 × 10²³

• 1.022 × 10²⁴

Answer 1

The total number of electrons present in 20 mL of water is 6.684 × 10²⁴.

Explanation:

20 mL H₂O = 20 g H₂O

= `20/18`

= 1.11 mole of water

1 molecule of H₂O contains 10 electrons.

∴ Total electrons in 20 mL

= 1.11 × 6.022 × 10²³ × 10

= 6.684 × 10²⁴ electrons