If 3.42 grams of Al2(SO4)3 are required, what mass of H2SO4 must be present?
what is the reaction?
It does not say. It gives me the equation. 2 Al(OH)3 + 3H2SO4 ----> Al2(SO4)3 + 6H2O
To find the mass of H2SO4 required, you need to calculate the molar mass of Al2(SO4)3 and use stoichiometry to relate it to H2SO4.
Here's how you can do it step by step:
1. Start by calculating the molar mass of Al2(SO4)3:
- This compound contains 2 aluminum atoms (Al), 3 sulfur atoms (S), and 12 oxygen atoms (O).
- The molar mass of each element can be found on the periodic table:
- Aluminum (Al): 26.98 g/mol
- Sulfur (S): 32.07 g/mol
- Oxygen (O): 16.00 g/mol
- Add up the contributions from each element:
- (2 * Al) + (3 * S) + (12 * O) = (2 * 26.98) + (3 * 32.07) + (12 * 16.00) = 342.15 g/mol
- So, the molar mass of Al2(SO4)3 is 342.15 g/mol.
2. Now that you know the molar mass of Al2(SO4)3, you can use stoichiometry to relate it to H2SO4.
- The balanced chemical equation for the reaction between Al2(SO4)3 and H2SO4 is:
- Al2(SO4)3 + 6H2SO4 → 3H2SO4 + 2Al2(SO4)3
- From the equation, you can see that 3 moles of H2SO4 are produced for every 1 mole of Al2(SO4)3 consumed.
- This means the molar ratio of Al2(SO4)3 to H2SO4 is 1:3.
3. Calculate the amount of H2SO4 required:
- You are given that 3.42 grams of Al2(SO4)3 are required.
- To convert grams to moles, divide the mass of Al2(SO4)3 by its molar mass:
- Moles of Al2(SO4)3 = mass of Al2(SO4)3 / molar mass of Al2(SO4)3
- Moles of Al2(SO4)3 = 3.42 g / 342.15 g/mol = 0.01 mol
- Since the molar ratio of Al2(SO4)3 to H2SO4 is 1:3, the moles of H2SO4 needed is three times the moles of Al2(SO4)3:
- Moles of H2SO4 = 3 * Moles of Al2(SO4)3
- Moles of H2SO4 = 3 * 0.01 mol = 0.03 mol
4. Finally, calculate the mass of H2SO4 required by multiplying the moles of H2SO4 by its molar mass:
- Mass of H2SO4 = Moles of H2SO4 * molar mass of H2SO4
- The molar mass of H2SO4 can be calculated in a similar way as above:
- Hydrogen (H) has a molar mass of 1.01 g/mol
- Sulfur (S) has a molar mass of 32.07 g/mol
- Oxygen (O) has a molar mass of 16.00 g/mol
- Molar mass of H2SO4 = (2 * H) + S + (4 * O) = (2 * 1.01) + 32.07 + (4 * 16.00) = 98.09 g/mol
- Now, calculate the mass of H2SO4:
- Mass of H2SO4 = 0.03 mol * 98.09 g/mol ≈ 2.94 grams
Therefore, approximately 2.94 grams of H2SO4 should be present for 3.42 grams of Al2(SO4)3.