Question

How many grams of hydrogen are found in a methane, CH4, sample that contains 24 grams of C?
Group of answer choices

about 8 grams

about 4 grams

about 2 grams

about 16 grams

Answer 1

To find out how many grams of hydrogen are found in a methane (CH₄) sample that contains 24 grams of carbon (C), we can follow these steps:

1. **Calculate the number of moles of carbon (C)** in the sample.
- The molar mass of carbon (C) is approximately 12 g/mol.
- Moles of C = mass of C / molar mass of C = 24 grams / 12 g/mol = 2 moles of C.

2. **Determine the number of moles of hydrogen (H)** in the methane molecule.
- The chemical formula for methane is CH₄, so each molecule of methane contains 1 atom of carbon and 4 atoms of hydrogen.
- Therefore, 1 mole of C corresponds to 4 moles of H.

3. **Calculate the moles of hydrogen (H)** corresponding to the 2 moles of carbon (C).
- Moles of H = 2 moles of C × 4 moles of H/mole of C = 8 moles of H.

4. **Convert moles of hydrogen (H) to grams**.
- The molar mass of hydrogen (H) is approximately 1 g/mol.
- Mass of H = moles of H × molar mass of H = 8 moles × 1 g/mol = 8 grams.

Therefore, the methane sample that contains 24 grams of C has about **8 grams** of hydrogen (H).

The correct answer is **about 8 grams**.