How many Lithium ions are present in 75.3 grams of lithium sulfate?

There are three steps to solving this problem:

1. Calculate the molar mass of lithium sulfate. The formula is Li2SO4. We know this because the lithium ion has a charge of +1 and sulfate ion is SO4 2-. The ratio of lithium ion to sulfate ion is 1 to 2 to give a net charge of zero.

2. Convert grams of lithium sulfate to moles

3. Find the number of lithium ions in the calculated number of moles of Li2SO4. The chemical formula indicates that there are two ions of lithium per formula unit, so moles of lithium sulfate is multiplied by 2 to get moles of lithium ions.

The molar mass of lithium sulfate is:

2(6.9 g/mol) + 32.1 g/mol + 4(16.0 g/mol) = 109.9 grams/mole

Moles of Li2SO4 = (75.3g)(1 mol/109.9 g) = 0.685 moles

lithium ions = (0.685 moles LiSO4)(2 Li/1 LiSO4)(6.02x10^23 ions/1 mol)

= 8.25 x 10^23 lithium ions