Question

H2O is identified as a compound with definite proportions. What are the proportions of each element?

Answer 1

H2O, or water, is a compound comprised of hydrogen and oxygen. In this molecule, there are two hydrogen (H) atoms and one oxygen (O) atom.

To determine the proportions of each element in H2O, we can look at the molar masses:
- The molar mass of hydrogen is approximately 1 gram per mole.
- The molar mass of oxygen is approximately 16 grams per mole.

Now, we calculate the total molar mass of H2O:
- Total mass = (2 × 1 g/mol) + (1 × 16 g/mol) = 2 g/mol + 16 g/mol = 18 g/mol.

Now we can find the proportion of each element by dividing the mass of each element by the total mass of the compound:

- Proportion of hydrogen: (2 g/mol) / (18 g/mol) ≈ 0.111, or 11.1%
- Proportion of oxygen: (16 g/mol) / (18 g/mol) ≈ 0.889, or 88.9%

Therefore, the proportions of each element in H2O are approximately 11.1% hydrogen and 88.9% oxygen.