To determine the number of potassium ions in 85 grams of potassium sulfate (K2SO4), you need to follow these steps:
1. Calculate the molar mass of potassium sulfate (K2SO4):
- Molar mass of K (potassium) = 39.10 g/mol
- Molar mass of S (sulfur) = 32.07 g/mol
- Molar mass of O (oxygen) = 16.00 g/mol
- Molar mass of K2SO4 = (2 * molar mass of K) + molar mass of S + (4 * molar mass of O)
- Molar mass of K2SO4 = (2 * 39.10 g/mol) + 32.07 g/mol + (4 * 16.00 g/mol) = 174.27 g/mol
2. Calculate the number of moles of potassium sulfate in 85 grams:
- Moles = Mass (g) / Molar mass (g/mol)
- Moles of K2SO4 = 85 g / 174.27 g/mol ≈ 0.4876 moles
3. Since there are 2 potassium ions (K+) in each formula unit of K2SO4, calculate the total number of potassium ions:
- Total number of potassium ions = Moles of K2SO4 * 2
- Total number of potassium ions = 0.4876 moles * 2 ≈ 0.9752 moles
4. Finally, convert the number of moles to the number of potassium ions:
- Number of potassium ions = Total number of potassium ions * Avogadro's number
- Number of potassium ions ≈ 0.9752 moles * 6.022 x 10^23 ions/mol ≈ 5.83 x 10^23 potassium ions
So, there are approximately 5.83 x 10^23 potassium ions in 85 grams of potassium sulfate (K2SO4).