Use this reaction to answer the question: 2KClO3 -> 2KCl + 3O2
If I start with 65g KClO3, how many mol O2 will be formed? How many g O2?
If I need to produce 299g KCl, how many mol of KClO3 do I need to start with? How many g KClO3?
To answer the first question: "If I start with 65g KClO3, how many moles of O2 will be formed? How many grams of O2?"
1. Start by finding the molar mass of KClO3.
- The molar mass of K (potassium) is 39.1 g/mol.
- The molar mass of Cl (chlorine) is 35.5 g/mol.
- The molar mass of O (oxygen) is 16.0 g/mol.
- Therefore, the molar mass of KClO3 is (39.1 + 35.5 + (3 * 16.0)) g/mol = 122.6 g/mol.
2. Calculate the number of moles of KClO3.
- Moles = Mass / Molar mass
- Moles = 65g / 122.6 g/mol ≈ 0.530 mol
3. Use the stoichiometry of the reaction to determine the mole ratio between KClO3 and O2.
- According to the balanced equation, 2 moles of KClO3 produce 3 moles of O2.
4. Calculate the number of moles of O2 produced.
- Moles of O2 = Moles of KClO3 * (3 moles O2 / 2 moles KClO3)
- Moles of O2 = 0.530 mol * (3/2) mol = 0.795 mol
5. Convert the moles of O2 into grams.
- Grams of O2 = Moles of O2 * Molar mass of O2
- Grams of O2 = 0.795 mol * 32.0 g/mol = 25.44 g
Therefore, starting with 65g of KClO3 would yield approximately 0.795 moles of O2 and 25.44 grams of O2.
To answer the second question: "If I need to produce 299g KCl, how many moles of KClO3 do I need to start with? How many grams of KClO3?"
1. Start by finding the molar mass of KCl.
- The molar mass of K (potassium) is 39.1 g/mol.
- The molar mass of Cl (chlorine) is 35.5 g/mol.
- Therefore, the molar mass of KCl is 39.1 + 35.5 = 74.6 g/mol.
2. Calculate the number of moles of KCl.
- Moles = Mass / Molar mass
- Moles = 299g / 74.6 g/mol ≈ 4.007 mol
3. Use the stoichiometry of the reaction to determine the mole ratio between KClO3 and KCl.
- According to the balanced equation, 2 moles of KClO3 produce 2 moles of KCl.
4. Calculate the number of moles of KClO3 required.
- Moles of KClO3 = Moles of KCl * (2 moles KClO3 / 2 moles KCl)
- Moles of KClO3 = 4.007 mol * (2/2) mol = 4.007 mol
5. Convert the moles of KClO3 into grams.
- Grams of KClO3 = Moles of KClO3 * Molar mass of KClO3
- Grams of KClO3 = 4.007 mol * 122.6 g/mol = 490.25 g
Therefore, to produce 299g of KCl, you would need approximately 4.007 moles of KClO3 and 490.25 grams of KClO3.