If 75.0 grams of water is decomposed into hydrogen and oxygen, how many grams of oxygen should be formed?
2H2O ==> 2H2 + O2
Convert 75.0g H2O to mols. mols = grams/molar mass
Use the coefficients in the equation to convert mols H2O to moles O2.
Convert moles O2 to grams. g = mols x molar mass
To determine the number of grams of oxygen formed when 75.0 grams of water is decomposed, we need to understand the chemical formula of water and the molar ratio between water and oxygen.
The chemical formula for water is H2O, which means each molecule of water contains two hydrogen atoms (H) and one oxygen atom (O).
To calculate the molar mass of water, we can add the atomic masses of hydrogen and oxygen together. The atomic mass of hydrogen is approximately 1.008 grams/mol, and the atomic mass of oxygen is about 16.00 grams/mol.
Therefore, the molar mass of water (H2O) is:
(2 * atomic mass of hydrogen) + atomic mass of oxygen
= (2 * 1.008 g/mol) + 16.00 g/mol
= 18.02 g/mol
Now, we can determine the number of moles of water using its given mass and molar mass. We divide the mass of water by its molar mass:
75.0 g / 18.02 g/mol ≈ 4.16 mol
From the balanced chemical equation of the decomposition of water:
2 H2O -> 2 H2 + O2
We can see that for every two moles of water, one mole of oxygen is produced. Therefore, we can use this ratio to calculate the number of moles of oxygen produced during the decomposition of 4.16 moles of water.
As per the ratio, 2 moles of H2O produce 1 mole of O2. So, 4.16 moles of H2O will produce:
(4.16 mol H2O) * (1 mol O2 / 2 mol H2O) = 2.08 mol O2
Finally, to determine the mass of oxygen produced, we multiply the number of moles of oxygen by its molar mass, which is approximately 32.00 grams per mole:
2.08 mol O2 * 32.00 g/mol ≈ 66.56 grams
Therefore, approximately 66.56 grams of oxygen should be formed when 75.0 grams of water is decomposed.