How Many Moles Are In These Samples?

Question

1. 15.0 g of copper (II) sulfate

2. 100 molecules (exactly) of sulfuric acid

3. 6.210 mg of ptassium oxide

Can you explain to meee?

Answer 1

One mole has one Gram molecular mass (weight) of the compound and contains 6.022 * 10^23 molecules.

1. 15.0 g of copper (II) sulfate

Divide 15.0 g by 159.608 g/mole to get the number of moles of Copper (II) sulfate.

2. 100 molecules (exactly) of sulfuric acid

Divide 100 molecules by 6.022 * 10^23 molecules/mole to get the number of moles of Sulfuric acid.

3. 6.210 mg of potassium oxide

6.210 mg = 0.00621 g

Divide 0.00621 g of Potassium oxide by 94.196 g/mole to get the number of moles of Potassium oxide.