Question

How many molecules are in 6.0g of sodium phosphate?

Answer 1

Answer:

2.2 x 10²² molecules.

Explanation:

• Firstly, we need to calculate the no. of moles in (6.0 g) sodium phosphate:

no. of moles = mass/molar mass = (6.0 g)/(163.94 g/mol) = 0.0366 mol.

• It is known that every mole of a molecule contains Avogadro's number (6.022 x 10²³) of molecules.

using cross multiplication:

1.0 mole of sodium phosphate contains → 6.022 x 10²³ molecules.

0.0366 mole of sodium phosphate contains → ??? molecules.

∴ The no. of molecules in  6.0 g of sodium phosphate = (6.022 x 10²³ molecules)(0.0366 mole)/(1.0 mole) = 2.2 x 10²² molecules.