What is the molecular formula for ethane?

Ethane is a simple alkane composed of two carbon atoms and six hydrogen atoms. To derive the molecular formula, you can start with the general formula for alkanes, which is CₙH₂ₙ₊₂, where n represents the number of carbon atoms in the molecule.

For ethane, with two carbon atoms (n = 2), you can substitute into the formula:

CₙH₂ₙ₊₂ becomes C₂H₂(2)+2, which simplifies to C₂H₆. This correctly indicates that ethane has six hydrogen atoms bonded to its two carbon atoms, confirming that the molecular formula for ethane is indeed C₂H₆.

The other options reflect different alkanes with varying numbers of carbon atoms and hydrogen atoms. For example, C₃H₈ represents propane, which contains three carbon atoms, while C₄H₁₀ and C₅H₁₂ correspond to butane and pentane, respectively. Thus, these options do not apply to ethane.