To calculate the percentage mass of ammonia (NH₃) in the cleaner, we need to use the balanced chemical equation provided and the information given.
The balanced chemical equation is:
2NH₄OH + H₂SO₄ → (NH₄)₂SO₄ + 2H₂O
From the equation, we can see that the ratio between NH₄OH and H₂SO₄ is 2:1.
1. Calculate the number of moles of H₂SO₄ used:
- Volume of H₂SO₄ solution = 37.3 cm³ = 0.0373 L
- Molarity of H₂SO₄ solution = 0.360 M
- Moles of H₂SO₄ = Molarity x Volume = 0.360 mol/L x 0.0373 L = 0.0134 mol
2. Since the ratio between NH₄OH and H₂SO₄ is 2:1, the number of moles of NH₄OH used is also 0.0134 mol.
3. Calculate the molar mass of NH₄OH:
- NH₄OH = 1(N) + 4(H) + 1(O) = 14.01 g/mol + 4.03 g/mol + 16.00 g/mol = 34.04 g/mol
4. Calculate the mass of NH₄OH used:
- Mass = Moles x Molar mass = 0.0134 mol x 34.04 g/mol = 0.454 g
5. Calculate the percentage mass of NH₃ in the cleaner:
- Percentage mass = (Mass of NH₃ / Mass of cleaner) x 100%
- The mass of NH₃ is twice the mass of NH₄OH used (from the balanced chemical equation).
- Mass of NH₃ = 2 x Mass of NH₄OH used = 2 x 0.454 g = 0.908 g
- Mass of cleaner = 5.37 g (given)
- Percentage mass of NH₃ = (0.908 g / 5.37 g) x 100% ≈ 16.9%
Therefore, the percentage mass of ammonia (NH₃) in the cleaner is approximately 16.9%.