How to Calculate the Molecular Weight of C2H4

To calculate the molecular weight of C₂H₄ (ethylene), you need to know the atomic weights of carbon (C) and hydrogen (H). The atomic weight of carbon is approximately 12.01 g/mol, and the atomic weight of hydrogen is approximately 1.008 g/mol.

Here’s the step-by-step calculation:

1. Identify the number of each type of atom in the molecule:
   • Carbon (C): 2 atoms
   • Hydrogen (H): 4 atoms
2. Multiply the number of atoms by their respective atomic weights:
   • Carbon: 2 atoms × 12.01 g/mol = 24.02 g/mol
   • Hydrogen: 4 atoms × 1.008 g/mol = 4.032 g/mol
3. Add the results together to get the molecular weight:
   • 24.02 g/mol (Carbon) + 4.032 g/mol (Hydrogen) = 28.052 g/mol

Therefore, the molecular weight of C₂H₄ is approximately 28.052 g/mol.