Calculate the number of sodium ions in 0.12 moles of Na2O??

1 mole of Na₂O contains 2 moles of Na⁺ ions (and 1 moles of O²⁻ ions).

No. of moles of Na⁺ ions = (0.12 mol) × 2 = 0.24 mol

2 moles Na ions/mole Na2O x 0.12 moles Na2O x 6.02x10^23 ions/mole = 1.4x10^23 Na ions