Question

assumed water volume. 10.0 ml

what is the calculates mass of water

what is the moles of water

atoms of H present

atoms of O present

Answer 1

volume = 10.0 mL

density of H2O = 1.0 g/mL

density = mass / volume

mass = density x volume = 1.0 x 10.0

mass = 10.0 g

2) moles = mass / molar mass

moles = 10.0 / 18.0

moles = 0.55

3) 1 mol H2O contain 2 x 6.023 x 10²³ H atoms

0.55 moles H2O contain 0.55 x 2 x 6.023 x 10²³ / 1 = 6.62 x 10²³ H atoms

H atoms = 6.62 x 10²³

4) 1 mol H2O contain 6.023 x 10²³ O atoms

0.55 mol H2O contain 0.55 x 6.023 x 10²³ = 3.31 x 10²³ O atoms

O atoms = 3.31 x 10²³