Question

Multi-Step Conversions (Always go through moles!)

Example: How many grams of water (H2O) will you need in order to have
3.22 x 1024 water molecules?

Answer 1

Mass of water needed : 96.3 g

Further explanation

A mole is a number of particles(atoms, molecules, ions) in a substance

This refers to the atomic total of the 12 gr C-12 which is equal to 6.02.10²³, so 1 mole = 6.02.10²³ particles

Can be formulated :

N = n x No

N = number of particles

n = mol

No = 6.02.10²³ = Avogadro's number

moles H₂O=

`\tt moles=(N)/(No)\\\\moles=(3.22* 10^(24))/(6.02* 10^(23))\\\\moles=5.35`

mass H₂O(MW=18 g/mol) :

`\tt mass=moles* MW\\\\mass=5.35* 18\\\\mass=96.3~g`