1. Calculate the number of moles of NaOH needed to react with 500.0 g of H₂SO₄.
- Molar mass of H₂SO₄ = 98.08 g/mol.
- Moles of H₂SO₄ = 500.0 g / 98.08 g/mol ≈ 5.098 mol.
- From the balanced equation, 1 mol H₂SO₄ reacts with 2 mol NaOH.
- Moles of NaOH = 2 × 5.098 mol ≈ 10.196 mol.
- Rounded to two decimal places: 10.19 mol.
2. Calculate the mass of NH₃ produced from 125 g of NCl₃.
- Molar mass of NCl₃ = 120.36 g/mol.
- Moles of NCl₃ = 125 g / 120.36 g/mol ≈ 1.0385 mol.
- From the balanced equation, 1 mol NCl₃ produces 1 mol NH₃.
- Moles of NH₃ = 1.0385 mol.
- Molar mass of NH₃ = 17.03 g/mol.
- Mass of NH₃ = 1.0385 mol × 17.03 g/mol ≈ 17.69 g.
- Rounded to one decimal place: 17.7 g.
3. Identify the limiting reactant and determine the mass of CO₂ produced from 25.0 g C₃H₈ and 75.0 g O₂.
- Molar mass of C₃H₈ = 44.10 g/mol; moles = 25.0 g / 44.10 g/mol ≈ 0.5669 mol.
- Molar mass of O₂ = 32.00 g/mol; moles = 75.0 g / 32.00 g/mol ≈ 2.3438 mol.
- From the balanced equation, 1 mol C₃H₈ requires 5 mol O₂.
- O₂ required for 0.5669 mol C₃H₈ = 5 × 0.5669 ≈ 2.8345 mol (but only 2.3438 mol available).
- Thus, O₂ is limiting.
- From the equation, 5 mol O₂ produce 3 mol CO₂.
- Moles of CO₂ = (3/5) × 2.3438 mol ≈ 1.4063 mol.
- Molar mass of CO₂ = 44.01 g/mol.
- Mass of CO₂ = 1.4063 mol × 44.01 g/mol ≈ 61.89 g.
- Rounded to one decimal place: 61.9 g.
4. Calculate grams of SO₂ produced when 152 g CS₂ react with 48.0 g O₂.
- Molar mass of CS₂ = 76.14 g/mol; moles = 152 g / 76.14 g/mol ≈ 1.996 mol.
- Molar mass of O₂ = 32.00 g/mol; moles = 48.0 g / 32.00 g/mol = 1.500 mol.
- From the balanced equation, 1 mol CS₂ requires 3 mol O₂.
- O₂ required for 1.996 mol CS₂ = 3 × 1.996 ≈ 5.988 mol (but only 1.500 mol available).
- Thus, O₂ is limiting.
- From the equation, 3 mol O₂ produce 2 mol SO₂.
- Moles of SO₂ = (2/3) × 1.500 mol = 1.000 mol.
- Molar mass of SO₂ = 64.07 g/mol.
- Mass of SO₂ = 1.000 mol × 64.07 g/mol = 64.07 g.
- Rounded to one decimal place: 64.1 g.
Parent Tip: Review the logic above to help your child master the concept of basic stoichiometry worksheet.
