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

To determine the number of lithium ions in 75.3 grams of lithium sulfate, we first need to calculate the number of moles of lithium sulfate present. Then, we can use the stoichiometry of the compound to find the number of moles of lithium ions.

Here are the steps to find the answer:

1. Find the molar mass of lithium sulfate (Li2SO4):
- The molar mass of lithium (Li) is approximately 6.94 g/mol.
- The molar mass of sulfur (S) is approximately 32.07 g/mol.
- The molar mass of oxygen (O) is approximately 16.00 g/mol.
- The molar mass of lithium sulfate (Li2SO4) is:
Molar mass = (2 * Li) + S + (4 * O) = (2 * 6.94) + 32.07 + (4 * 16.00) = 109.94 g/mol.

2. Calculate the number of moles of lithium sulfate:
- Moles = Mass (g) / Molar mass (g/mol)
- Moles = 75.3 g / 109.94 g/mol ≈ 0.685 mol.

3. Use the stoichiometric ratio to find the moles of lithium ions:
- From the chemical formula of lithium sulfate (Li2SO4), we can see that each formula unit contains 2 lithium ions (Li2).
- So, the number of moles of lithium ions = 2 * moles of lithium sulfate = 2 * 0.685 mol = 1.37 mol.

4. Convert moles to the number of lithium ions:
- Avogadro's number tells us that 1 mole of any substance contains 6.022 x 10^23 entities (atoms, ions, molecules, etc.).
- Therefore, to find the number of lithium ions, we multiply the moles by Avogadro's number:
Number of lithium ions = Moles of lithium ions * Avogadro's number
Number of lithium ions = 1.37 mol * 6.022 x 10^23 ions/mol ≈ 8.25 x 10^23 lithium ions.

So, there are approximately 8.25 x 10^23 lithium ions in 75.3 grams of lithium sulfate.