C9H8 Index of chemical compounds with the same molecular formula From Wikipedia, the free encyclopedia The molecular formula C9H8 (molar mass: 126.24 g/mol, exact mass: 126.1409 u) may refer to: Indene Isoindene This set index page lists chemical structure articles associated with the same molecular formula.If an internal link led you here, you may wish to change the link to point directly to the intended article. More information Related molecular formulas ... Related molecular formulas C9H10 C8H6 C9H8 C10H10 C9H6 Close Related Articles