Calculate the number of potassium ions present in 7.45 g of potassium oxide
How many mols K2O in 7.45 g K2O? That's
mols K2O = 7.45 grams/molar mass K2O = ?
Looking at the formula you can see there are twice as many mols K^+ as there are in (7.45 g/molar mass K2O) of K2O.
Then you know there are 6.02E23 ions in 1 mol ions so how many atoms do you have?
To calculate the number of potassium ions present in a given amount of potassium oxide, we need to know the molar mass of potassium oxide and the number of potassium ions present in one formula unit of the compound.
1. Find the molar mass of potassium oxide (K2O):
- The molar mass of potassium (K) is 39.10 g/mol.
- Oxygen (O) has a molar mass of 16.00 g/mol.
- Since there are two potassium atoms and one oxygen atom in one formula unit of potassium oxide, we add the molar masses to get the total molar mass of K2O:
Molar mass of K2O = (2 x 39.10 g/mol) + (1 x 16.00 g/mol) = 94.20 g/mol.
2. Calculate the number of moles of potassium oxide:
- Convert the given mass of potassium oxide (7.45 g) to moles by dividing it by the molar mass:
Moles of K2O = 7.45 g / 94.20 g/mol = 0.0790 mol.
3. Determine the number of moles of potassium ions:
- Since there are two potassium ions (K+) in one formula unit of K2O, multiply the moles of K2O by 2 to find the moles of potassium ions:
Moles of K+ = 0.0790 mol x 2 = 0.158 mol.
4. Finally, determine the number of potassium ions:
- To convert moles to the number of ions, multiply the moles of potassium ions by Avogadro's number (6.022 x 10^23 ions/mol):
Number of K+ ions = 0.158 mol x (6.022 x 10^23 ions/mol) ≈ 9.51 x 10^22 potassium ions.
Therefore, there are approximately 9.51 x 10^22 potassium ions present in 7.45 g of potassium oxide.