Oxalic Acid Dihydrate [6153-56-6] is a chemically defined substance with the molecular formula C2H2O4 and a molecular weight of 90.03. It sublimes at an unspecified temperature while it decomposes upon melting at 188.9 °C as reported by NTP. This compound carries a danger signal word due to its acute toxicity when ingested, as indicated by the hazard statement "Harmful if swallowed.

• CAS Number: 6153-56-6
• Molecular Formula: C2H2O4
• Melting Point: 188.9 °C — decomposes
• Boiling Point: Sublimes
• GHS Signal Word: Danger
• Molecular Weight: 90.03
• Vapour Density: 4.3
• Exact Mass: 89.99530854
• Hazard Statements:
• H302: Harmful if swallowed [Warning Acute toxicity, oral]