How many aluminum ions are in 12 grams of aluminum oxide?
1-LVDCPN > 09-18-2018, 06:16 AM
Aluminium oxide has the formula Al22O33. This has a formula mass of 101.96 g mol−1−1.
That means that 12 g of Al22O33 contain 12 g / 101.96 g mol−1−1 = 0.118 moles of Al22O33.
Each Al22O33 formula unit contains two Al3+3+ ions, so there are 2 x 0.118 mol = 0.235 moles of Al3+3+ ions.
If you want an actual number, you can multiply that by Avogadro’s constant: 0.235 mol x 6.022 x 102323 mol−1−1 = 1.42 x 102323 ions.