Oxalic Acid, Ethanedioic Acid, Oxalic Acid Dihydrate, 144-62-7

📑 Oxalic Acid (CAS 144-62-7)

General Information

• Chemical Name: Ethanedioic Acid, Dihydrate; Oxalic Acid Dihydrate

• Chemical Formula: C₂H₂O₄ · 2H₂O

• Appearance: White crystalline powder

• Packaging: 25 kg bags

Production Methods

• Classical method: Oxidation of carbohydrates (e.g., glucose) with nitric acid or air in the presence of vanadium pentoxide.

• Alternative precursors: Glycolic acid, ethylene glycol.

• Modern method: Oxidative carbonylation of alcohols → oxalic acid diesters.

4ROH+4CO+O2→2(CO2R)2+2H2O

Natural Sources

• Rhubarb (calcium oxalate form)

• Sorrel (sodium oxalate form)

• Spinach, tomatoes, and other leafy plants

Applications

🏭 Industrial

• Mordant in textile dyeing

• Rust remover and cleaning agent for metal surfaces

• Electronics and ceramics cleaning

• Wood and marble bleaching and polishing

🌱 Agriculture & Beekeeping

• Varroa mite control in honeybee colonies (drip or vaporization methods)

• Applied in sugar syrup solutions during broodless periods

🧪 Analytical Chemistry

• Quantitative analysis of calcium (precipitation as calcium oxalate)

• Reducing agent in manganometry

• Used in antimony salt analysis

Biological Effects

• Human body: Combines with calcium → calcium oxalate → kidney stone risk.

• Nutrition: Found in spinach, cocoa, nuts; excessive intake reduces mineral absorption.

• Plants: Stored as calcium oxalate crystals; role in detoxification and defense.

Environmental & Industrial Processes

• Leaching: Dissolves Fe₂O₃ minerals for purification.

• Wastewater treatment: Precipitates contaminants, adjusts pH.

• Mining: Feldspar concentration and process optimization.

Safety & Precautions

• Irritant and harmful to skin and respiratory system.

• Use protective clothing, gloves, goggles, and mask.

• Work in well-ventilated areas.

• Keep away from food products.

FAQ

• How is oxalic acid used in varroa control? By dripping or vaporizing inside the hive.

• What are the hazards? Irritant, toxic, kidney stone risk.

• Difference between oxalic acid and dihydrate? Dihydrate contains crystallized water, lower acid activity.

• How to use as rust remover? Dissolve in water, apply to rusted surface, scrub, rinse thoroughly.

Synonyms

• Ethanedioic acid

• Oxalic acid

• Aktisal, Aquisal

• NSC 132055, NSC 151956, NSC 62774, NSC 76990

• Ultraplast Activate S 52

• DeerClean

• MeSH ID: D019815

📊 Oxalic Acid (CAS 144-62-7) – Sectoral Suitability Table