Based on the Law of Conservation of Mass, the total mass of the reactants in a chemical reaction must equal the total mass of the products. In the given reaction where water (H2O) is heated to produce oxygen (O2) and hydrogen gas (H2), the total mass of the reactant (water) must be equal to the total mass of the products (oxygen and hydrogen gas).
To find the mass of the products formed when 28.75 g of water is heated, we need to consider the molar masses of water, oxygen, and hydrogen.
1. Calculate the molar mass of water (H2O):
- Molar mass of hydrogen (H): 1.01 g/mol
- Molar mass of oxygen (O): 16.00 g/mol
- Molar mass of water (H2O): 2(1.01 g/mol) + 16.00 g/mol = 18.02 g/mol
2. Determine the number of moles of water in 28.75 g:
- Moles of water = Mass of water / Molar mass of water
- Moles of water = 28.75 g / 18.02 g/mol = 1.595 mol
3. Apply the mole ratio from the balanced chemical equation to find the moles of oxygen and hydrogen produced:
- Balanced equation: 2H2O -> 2H2 + O2
- Moles of water = Moles of oxygen = Moles of hydrogen
- Moles of oxygen = Moles of hydrogen = 1.595 mol
4. Calculate the mass of oxygen and hydrogen produced:
- Mass of oxygen = Moles of oxygen x Molar mass of oxygen
- Mass of oxygen = 1.595 mol x 16.00 g/mol = 25.52 g
- Mass of hydrogen = Moles of hydrogen x Molar mass of hydrogen
- Mass of hydrogen = 1.595 mol x 2.02 g/mol = 3.22 g
Therefore, when 28.75 g of water is heated, 25.52 g of oxygen and 3.22 g of hydrogen gas are produced according to the Law of Conservation of Mass.
