C2O4

The molecular formula C2O4 (molar mass: 88.02 g/mol) may refer to:


 * Oxalate (ethanedioate)
 * Dioxetanediones:
 * 1,2-Dioxetanedione (1,2-dioxetane-3,4-dione)
 * 1,3-Dioxetanedione (1,3-dioxetane-2,4-dione)