1. Understand the Dissociation
Sodium chloride (NaCl) dissolves in water to form sodium ions (Na+) and chloride ions (Cl-):
NaCl(s) → Na+(aq) + Cl-(aq)
This means each formula unit of NaCl produces two ions (one Na+ and one Cl-).
2. Calculate the Number of Formula Units
* Avogadro's number tells us there are 6.022 x 10^23 formula units in one mole of any substance.
* Therefore, a 6.58 mole sample of NaCl contains:
6.58 moles * (6.022 x 10^23 formula units/mole) = 3.96 x 10^24 formula units
3. Calculate the Number of Ions
* Since each formula unit of NaCl produces two ions, a 6.58 mole sample will have:
3.96 x 10^24 formula units * 2 ions/formula unit = 7.92 x 10^24 ions
Therefore, there are approximately 7.92 x 10^24 ions in a 6.58 mole sample of NaCl.
