A hydrocarbon of pentane has two isomeric forms—n-pentane and iso-pentane. The molecular formula of the n-pentane is C5H12. Predict the molecular formula of the iso-pentane.

A hydrocarbon of pentane has three isomeric forms:

CH₃-CH₂-CH₂-CH₂-CH₃ n-pentane (normal pentane) (C₅H₁₂)

CH₃-CH-CH₂-CH₃ iso-pentane (C₅H₁₂)
I
CH₃

CH₃
I
CH₃-C-CH₃ neo-pentane (C₅H₁₂)
I
CH₃

Isomers have the same qualitative and quantitative composition, but different structure.