1. Calculate the molar mass of CH4:
- Molar mass of CH4 = (1 x atomic mass of C) + (4 x atomic mass of H)
- Molar mass of CH4 = (1 x 12.01 g/mol) + (4 x 1.008 g/mol) = 16.04 g/mol
2. Calculate the mass of each element in 1 mole of CH4:
- Mass of carbon in 1 mole of CH4 = 12.01 g/mol
- Mass of hydrogen in 1 mole of CH4 = 4 x 1.008 g/mol = 4.032 g/mol
3. Calculate the mass percentage of each element:
- Mass percentage of carbon = (Mass of carbon / Molar mass of CH4) x 100%
- Mass percentage of carbon = (12.01 g/mol / 16.04 g/mol) x 100% = 75.0%
- Mass percentage of hydrogen = (Mass of hydrogen / Molar mass of CH4) x 100%
- Mass percentage of hydrogen = (4.032 g/mol / 16.04 g/mol) x 100% = 25.0%
Therefore, the percentage composition of CH4 is approximately 75.0% carbon and 25.0% hydrogen.
