What are the chemical formulas for methane, ethane, propane, and butane?

The chemical formulas for these hydrocarbons are:

• Methane: CH₄
• Ethane: C₂H₆
• Propane: C₃H₈
• Butane: C₄H₁₀

Methane is the simplest alkane, and as the molecular weight increases, so do the number of carbon and hydrogen atoms.