Synonyms: 2-Butanone; ethyl methyl ketone; MEK; Methyl acetone CAS No.: 78-93-3 Molecular Weight: 72.11 Chemical Formula: CH3COCH2CH3 Product Codes: J.T. Baker: 5385, 9214, 9319, 9323, 9414, Q531 Mallinckrodt: 6206, 6233, 6240, 6243