Oxalic acid (CAS 144-62-7) — formula C2H2O4, molecular weight 90.03.
| CAS Number | 144-62-7 |
|---|---|
| Molecular Formula | C2H2O4 |
| Molecular Weight | 90.03 |
| Melting Point | 189.5 |
| LogP | -0.3 |
| Applications | Uses: Used in metal cleaning, chemical synthesis, dye and rubber manufacturing, and textile stripping, finishing, Also used as a disinfectant (swimming pool and drainage system) and bathroom sanitizer, [ACGIH] Several species of plants contain soluble and insoluble oxalate salts. [Olson, p. 360] Used in photography (toner and platinum printing), Also used as a mordant in textile dyeing, [www.ci.tucson.az.us, arthazards, medium.html], Using Disinfectants or Biocides [Category: Clean], Photographic Processing [Category: Other], Textiles (Printing, Dyeing, or Finishing) [Category: Industry], Textile arts [Category: Hobbies], Applying metallic patinas [Category: Hobbies], SCOURING AGENT IN TEXTILE FINISHING, STRIPPING, CLEANING, FOR BLEACH & STAIN REMOVER, RUST, GREASE, AND WAX REMOVING AGENT IN METAL CLEANING, CHEM INT, AS ANALYTICAL REAGENT, IN CALICO PRINTING & DYEING, BLEACHING STRAW (HATS) & LEATHER, MFR OXALATES, BLUE INK, REMOVING PAINT OR VARNISH, RUST OR INK STAINS, CLEANING WOOD, MFR CELLULOID, INT & DYES, IN METAL POLISHES, IN INDIGO DYEING, IN PURIFYING METHANOL, FOR DECOLORIZING CRUDE GLYCEROL, FOR STABILIZING HYDROCYANIC ACID, AS GENERAL REDUCING AGENT, IN CERAMICS & PIGMENTS, IN METALLURGY AS CLEANSER, IN PAPER INDUSTRY, IN PHOTOGRAPHY, IN PROCESS ENGRAVING, IN RUBBER MFR INDUSTRY, IN MAKING GLUCOSE FROM STARCH, AS CONDENSING AGENT IN ORG CHEMISTRY, VET: IN 5% SOLN WITH 5% MALONIC ACID AS HEMOSTATIC AGENT, OXALIC ACID & OXALATE SALTS ARE SOMETIMES USED AS ANTICOAGULANTS IN BLOOD SPECIMENS DRAWN FOR CHEMICAL ANALYSIS., AUTOMOBILE RADIATOR CLEANSER, RARE-EARTH PROCESSING, IT IS A COMPONENT OF HOUSEHOLD FORMULATIONS FOR CLEANING ALUMINUM, SILVER, COPPER AND COPPER ALLOYS, IT IS USED IN THE REFINING OF TALL OIL, THE PURIFICATION OF CRUDE NATURE GUMS, AS AN ADDITIVE FOR BREAKING WATER IN OIL EMULSIONS, AND A SOIL TREATING MATERIAL TO INCREASE THE AVAILABILITY OF PHOSPHATE FERTILIZERS. SODIUM OXALATE IS ADDED TO ARTILLERY AMMUNITION TO SUPPRESS FLASHING, Oxalic acid and oxalates are abundantly present in many plants, most notably fat hen (lamb's quarters), sorrel, and Oxalis species. The root and, or leaves of rhubarb and buckwheat are listed being high in oxalic acid.[8] Other edible plants that contain significant concentrations of oxalic acid include—in decreasing order—star fruit (carambola), black pepper, parsley, poppy seed, amaranth, spinach, chard, beets, cocoa, chocolate, most nuts, most berries, and beans. (L618), Use Classification: Fragrance Ingredients, Cosmetics -> Chelating, Industry Uses: Deodorizer, Plating agent, Solvent, Etching agent, Solids separation (precipitating) agent, not otherwise specified, Photosensitive agent, Chelating agent, Anti-scaling agent, Dye, Cleaning agent, Reducing agent, Soil amendments (fertilizers), Catalyst, Corrosion inhibitor, Not Known or Reasonably Ascertainable, Consumer Uses: pH regulating agent, Bleaching agent, Household Products: Information on 47 consumer products that contain Oxalic acid in the following categories is provided:, • Auto Products, • Commercial, Institutional, • Home Maintenance, • Inside the Home, Methods of Manufacturing: MADE BY PASSING CARBON MONOXIDE INTO CONCENTRATED SODIUM HYDROXIDE OR BY HEATING SODIUM FORMATE IN PRESENCE OF SODIUM HYDROXIDE OR SODIUM CARBONATE., OXALIC ACID IS PRODUCED COMMERCIALLY BY NITRIC ACID OXIDATION OF STARCH, SUGAR, OR ETHYLENE GLYCOL, OXALIC ACID IS A CO-PRODUCT OF THE FERMENTATION OF MOLASSES TO CITRIC ACID. OXALIC ACID CAN BE MADE BY FUSING SAWDUST (OR OTHER FORMS OF CELLULOSE) WITH A MIXTURE OF SODIUM HYDROXIDE AND POTASSIUM HYDROXIDE. TEXACO WAS GRANTED A PATENT IN 1973 FOR THE ELECTROLYTIC SYNTHESIS OF OXALIC ACID FROM CARBON DIOXIDE AND HYDROGEN., Formulations, Preparations: Technical (crystals and powder), chemically pure: a grade designation signifying a minimum of impurities, but not 100% purity., THE COMMERCIAL PRODUCT IS COMPRISED OF WHITE TO COLORLESS MONOCLINIC PRISMS OR GRANULES CONTAINING 71.42 wt% ANHYDROUS OXALIC ACID AND 28.58 wt% WATER, Consumption Patterns: 27% FOR TEXTILE FINISHING, STRIPPING AND CLEANING, 27% FOR METAL AND EQUIPMENT CLEANING, 25% AS A CHEMICAL INTERMEDIATE, 2% FOR LEATHER TANNING, 19% FOR MISC APPLICATIONS (1971), 33% FOR TEXTILE, APPLICATIONS, 20% FOR METAL, 7% FOR LEATHER, 20% FOR OXALATES, AND 20% FOR OTHER USE (1983), U.S. Production: 2023: 2, 500, 000 - <4, 000, 000 lb, 2022: 2, 2021: 2, 2020: 1, 000 - <2, (1972) 1.0X10+10 G, (1974) 8.17X10+9 G, U.S. Imports: (1972) 8.6X10+8 G, (1975) 1.73X10+9 G, (1984) 9.31X10+9 g, U.S. Exports: (1972) NEGLIGIBLE, 1.68X10+8 g, General Manufacturing Information: Not Known or Reasonably Ascertainable, All Other Chemical Product and Preparation Manufacturing, Photographic Film, Paper, Plate, and Chemical Manufacturing, Plastics Material and Resin Manufacturing, Paint and Coating Manufacturing, All Other Basic Organic Chemical Manufacturing, Miscellaneous Manufacturing, Pesticide, Fertilizer, and Other Agricultural Chemical Manufacturing, Mining (except Oil and Gas) and support activities, Soap, Cleaning Compound, and Toilet Preparation Manufacturing, Ethanedioic acid: ACTIVE, IT IS A PRODUCT OF THE METABOLISM OF MANY MOLDS, SEVERAL SPECIES OF PENICILLIUM & ASPERGILLUS CONVERT SUGAR INTO CALCIUM OXALATE WITH 90% YIELD UNDER OPTIMUM CONDITIONS., BY 1983, MOST USA PRODUCERS, HAD ENDED PRODUCTION AND USA DEMAND HAS BEEN FILLED BY IMPORTS, PRINCIPALLY FROM CHINA AND BRAZIL |
Documented applications: Uses: Used in metal cleaning, chemical synthesis, dye and rubber manufacturing, and textile stripping, finishing, Also used as a disinfectant (swimming pool and drainage system) and bathroom sanitizer, [ACGIH] Several species of plants contain soluble and insoluble oxalate salts. [Olson, p. 360] Used in photography (toner and platinum printing), Also used as a mordant in textile dyeing, [www.ci.tucson.az.us, arthazards, medium.html], Using Disinfectants or Biocides [Category: Clean], Photographic Processing [Category: Other], Textiles (Printing, Dyeing, or Finishing) [Category: Industry], Textile arts [Category: Hobbies], Applying metallic patinas [Category: Hobbies], SCOURING AGENT IN TEXTILE FINISHING, STRIPPING, CLEANING, FOR BLEACH & STAIN REMOVER, RUST, GREASE, AND WAX REMOVING AGENT IN METAL CLEANING, CHEM INT, AS ANALYTICAL REAGENT, IN CALICO PRINTING & DYEING, BLEACHING STRAW (HATS) & LEATHER, MFR OXALATES, BLUE INK, REMOVING PAINT OR VARNISH, RUST OR INK STAINS, CLEANING WOOD, MFR CELLULOID, INT & DYES, IN METAL POLISHES, IN INDIGO DYEING, IN PURIFYING METHANOL, FOR DECOLORIZING CRUDE GLYCEROL, FOR STABILIZING HYDROCYANIC ACID, AS GENERAL REDUCING AGENT, IN CERAMICS & PIGMENTS, IN METALLURGY AS CLEANSER, IN PAPER INDUSTRY, IN PHOTOGRAPHY, IN PROCESS ENGRAVING, IN RUBBER MFR INDUSTRY, IN MAKING GLUCOSE FROM STARCH, AS CONDENSING AGENT IN ORG CHEMISTRY, VET: IN 5% SOLN WITH 5% MALONIC ACID AS HEMOSTATIC AGENT, OXALIC ACID & OXALATE SALTS ARE SOMETIMES USED AS ANTICOAGULANTS IN BLOOD SPECIMENS DRAWN FOR CHEMICAL ANALYSIS., AUTOMOBILE RADIATOR CLEANSER, RARE-EARTH PROCESSING, IT IS A COMPONENT OF HOUSEHOLD FORMULATIONS FOR CLEANING ALUMINUM, SILVER, COPPER AND COPPER ALLOYS, IT IS USED IN THE REFINING OF TALL OIL, THE PURIFICATION OF CRUDE NATURE GUMS, AS AN ADDITIVE FOR BREAKING WATER IN OIL EMULSIONS, AND A SOIL TREATING MATERIAL TO INCREASE THE AVAILABILITY OF PHOSPHATE FERTILIZERS. SODIUM OXALATE IS ADDED TO ARTILLERY AMMUNITION TO SUPPRESS FLASHING, Oxalic acid and oxalates are abundantly present in many plants, most notably fat hen (lamb's quarters), sorrel, and Oxalis species. The root and, or leaves of rhubarb and buckwheat are listed being high in oxalic acid.[8] Other edible plants that contain significant concentrations of oxalic acid include—in decreasing order—star fruit (carambola), black pepper, parsley, poppy seed, amaranth, spinach, chard, beets, cocoa, chocolate, most nuts, most berries, and beans. (L618), Use Classification: Fragrance Ingredients, Cosmetics -> Chelating, Industry Uses: Deodorizer, Plating agent, Solvent, Etching agent, Solids separation (precipitating) agent, not otherwise specified, Photosensitive agent, Chelating agent, Anti-scaling agent, Dye, Cleaning agent, Reducing agent, Soil amendments (fertilizers), Catalyst, Corrosion inhibitor, Not Known or Reasonably Ascertainable, Consumer Uses: pH regulating agent, Bleaching agent, Household Products: Information on 47 consumer products that contain Oxalic acid in the following categories is provided:, • Auto Products, • Commercial, Institutional, • Home Maintenance, • Inside the Home, Methods of Manufacturing: MADE BY PASSING CARBON MONOXIDE INTO CONCENTRATED SODIUM HYDROXIDE OR BY HEATING SODIUM FORMATE IN PRESENCE OF SODIUM HYDROXIDE OR SODIUM CARBONATE., OXALIC ACID IS PRODUCED COMMERCIALLY BY NITRIC ACID OXIDATION OF STARCH, SUGAR, OR ETHYLENE GLYCOL, OXALIC ACID IS A CO-PRODUCT OF THE FERMENTATION OF MOLASSES TO CITRIC ACID. OXALIC ACID CAN BE MADE BY FUSING SAWDUST (OR OTHER FORMS OF CELLULOSE) WITH A MIXTURE OF SODIUM HYDROXIDE AND POTASSIUM HYDROXIDE. TEXACO WAS GRANTED A PATENT IN 1973 FOR THE ELECTROLYTIC SYNTHESIS OF OXALIC ACID FROM CARBON DIOXIDE AND HYDROGEN., Formulations, Preparations: Technical (crystals and powder), chemically pure: a grade designation signifying a minimum of impurities, but not 100% purity., THE COMMERCIAL PRODUCT IS COMPRISED OF WHITE TO COLORLESS MONOCLINIC PRISMS OR GRANULES CONTAINING 71.42 wt% ANHYDROUS OXALIC ACID AND 28.58 wt% WATER, Consumption Patterns: 27% FOR TEXTILE FINISHING, STRIPPING AND CLEANING, 27% FOR METAL AND EQUIPMENT CLEANING, 25% AS A CHEMICAL INTERMEDIATE, 2% FOR LEATHER TANNING, 19% FOR MISC APPLICATIONS (1971), 33% FOR TEXTILE, APPLICATIONS, 20% FOR METAL, 7% FOR LEATHER, 20% FOR OXALATES, AND 20% FOR OTHER USE (1983), U.S. Production: 2023: 2, 500, 000 - <4, 000, 000 lb, 2022: 2, 2021: 2, 2020: 1, 000 - <2, (1972) 1.0X10+10 G, (1974) 8.17X10+9 G, U.S. Imports: (1972) 8.6X10+8 G, (1975) 1.73X10+9 G, (1984) 9.31X10+9 g, U.S. Exports: (1972) NEGLIGIBLE, 1.68X10+8 g, General Manufacturing Information: Not Known or Reasonably Ascertainable, All Other Chemical Product and Preparation Manufacturing, Photographic Film, Paper, Plate, and Chemical Manufacturing, Plastics Material and Resin Manufacturing, Paint and Coating Manufacturing, All Other Basic Organic Chemical Manufacturing, Miscellaneous Manufacturing, Pesticide, Fertilizer, and Other Agricultural Chemical Manufacturing, Mining (except Oil and Gas) and support activities, Soap, Cleaning Compound, and Toilet Preparation Manufacturing, Ethanedioic acid: ACTIVE, IT IS A PRODUCT OF THE METABOLISM OF MANY MOLDS, SEVERAL SPECIES OF PENICILLIUM & ASPERGILLUS CONVERT SUGAR INTO CALCIUM OXALATE WITH 90% YIELD UNDER OPTIMUM CONDITIONS., BY 1983, MOST USA PRODUCERS, HAD ENDED PRODUCTION AND USA DEMAND HAS BEEN FILLED BY IMPORTS, PRINCIPALLY FROM CHINA AND BRAZIL.
Oxalic acid is a chemical compound with CAS registry number 144-62-7 and molecular formula C2H2O4 (molecular weight 90.03).
CAS number: 144-62-7
Its molecular formula C2H2O4 comprises 2 C, 2 H, 4 O atoms.
Also known as: Oxalic acid · 草酸
The CAS registry number of Oxalic acid is 144-62-7.
Molecular formula C2H2O4, molecular weight 90.03.
It is also registered under: Oxalic acid, 草酸.
Recorded applications: Uses: Used in metal cleaning, chemical synthesis, dye and rubber manufacturing, and textile stripping, finishing, Also used as a disinfectant (swimming pool and drainage system) and bathroom sanitizer, [ACGIH] Several species of plants contain soluble and insoluble oxalate salts. [Olson, p. 360] Used in photography (toner and platinum printing), Also used as a mordant in textile dyeing, [www.ci.tucson.az.us, arthazards, medium.html], Using Disinfectants or Biocides [Category: Clean], Photographic Processing [Category: Other], Textiles (Printing, Dyeing, or Finishing) [Category: Industry], Textile arts [Category: Hobbies], Applying metallic patinas [Category: Hobbies], SCOURING AGENT IN TEXTILE FINISHING, STRIPPING, CLEANING, FOR BLEACH & STAIN REMOVER, RUST, GREASE, AND WAX REMOVING AGENT IN METAL CLEANING, CHEM INT, AS ANALYTICAL REAGENT, IN CALICO PRINTING & DYEING, BLEACHING STRAW (HATS) & LEATHER, MFR OXALATES, BLUE INK, REMOVING PAINT OR VARNISH, RUST OR INK STAINS, CLEANING WOOD, MFR CELLULOID, INT & DYES, IN METAL POLISHES, IN INDIGO DYEING, IN PURIFYING METHANOL, FOR DECOLORIZING CRUDE GLYCEROL, FOR STABILIZING HYDROCYANIC ACID, AS GENERAL REDUCING AGENT, IN CERAMICS & PIGMENTS, IN METALLURGY AS CLEANSER, IN PAPER INDUSTRY, IN PHOTOGRAPHY, IN PROCESS ENGRAVING, IN RUBBER MFR INDUSTRY, IN MAKING GLUCOSE FROM STARCH, AS CONDENSING AGENT IN ORG CHEMISTRY, VET: IN 5% SOLN WITH 5% MALONIC ACID AS HEMOSTATIC AGENT, OXALIC ACID & OXALATE SALTS ARE SOMETIMES USED AS ANTICOAGULANTS IN BLOOD SPECIMENS DRAWN FOR CHEMICAL ANALYSIS., AUTOMOBILE RADIATOR CLEANSER, RARE-EARTH PROCESSING, IT IS A COMPONENT OF HOUSEHOLD FORMULATIONS FOR CLEANING ALUMINUM, SILVER, COPPER AND COPPER ALLOYS, IT IS USED IN THE REFINING OF TALL OIL, THE PURIFICATION OF CRUDE NATURE GUMS, AS AN ADDITIVE FOR BREAKING WATER IN OIL EMULSIONS, AND A SOIL TREATING MATERIAL TO INCREASE THE AVAILABILITY OF PHOSPHATE FERTILIZERS. SODIUM OXALATE IS ADDED TO ARTILLERY AMMUNITION TO SUPPRESS FLASHING, Oxalic acid and oxalates are abundantly present in many plants, most notably fat hen (lamb's quarters), sorrel, and Oxalis species. The root and, or leaves of rhubarb and buckwheat are listed being high in oxalic acid.[8] Other edible plants that contain significant concentrations of oxalic acid include—in decreasing order—star fruit (carambola), black pepper, parsley, poppy seed, amaranth, spinach, chard, beets, cocoa, chocolate, most nuts, most berries, and beans. (L618), Use Classification: Fragrance Ingredients, Cosmetics -> Chelating, Industry Uses: Deodorizer, Plating agent, Solvent, Etching agent, Solids separation (precipitating) agent, not otherwise specified, Photosensitive agent, Chelating agent, Anti-scaling agent, Dye, Cleaning agent, Reducing agent, Soil amendments (fertilizers), Catalyst, Corrosion inhibitor, Not Known or Reasonably Ascertainable, Consumer Uses: pH regulating agent, Bleaching agent, Household Products: Information on 47 consumer products that contain Oxalic acid in the following categories is provided:, • Auto Products, • Commercial, Institutional, • Home Maintenance, • Inside the Home, Methods of Manufacturing: MADE BY PASSING CARBON MONOXIDE INTO CONCENTRATED SODIUM HYDROXIDE OR BY HEATING SODIUM FORMATE IN PRESENCE OF SODIUM HYDROXIDE OR SODIUM CARBONATE., OXALIC ACID IS PRODUCED COMMERCIALLY BY NITRIC ACID OXIDATION OF STARCH, SUGAR, OR ETHYLENE GLYCOL, OXALIC ACID IS A CO-PRODUCT OF THE FERMENTATION OF MOLASSES TO CITRIC ACID. OXALIC ACID CAN BE MADE BY FUSING SAWDUST (OR OTHER FORMS OF CELLULOSE) WITH A MIXTURE OF SODIUM HYDROXIDE AND POTASSIUM HYDROXIDE. TEXACO WAS GRANTED A PATENT IN 1973 FOR THE ELECTROLYTIC SYNTHESIS OF OXALIC ACID FROM CARBON DIOXIDE AND HYDROGEN., Formulations, Preparations: Technical (crystals and powder), chemically pure: a grade designation signifying a minimum of impurities, but not 100% purity., THE COMMERCIAL PRODUCT IS COMPRISED OF WHITE TO COLORLESS MONOCLINIC PRISMS OR GRANULES CONTAINING 71.42 wt% ANHYDROUS OXALIC ACID AND 28.58 wt% WATER, Consumption Patterns: 27% FOR TEXTILE FINISHING, STRIPPING AND CLEANING, 27% FOR METAL AND EQUIPMENT CLEANING, 25% AS A CHEMICAL INTERMEDIATE, 2% FOR LEATHER TANNING, 19% FOR MISC APPLICATIONS (1971), 33% FOR TEXTILE, APPLICATIONS, 20% FOR METAL, 7% FOR LEATHER, 20% FOR OXALATES, AND 20% FOR OTHER USE (1983), U.S. Production: 2023: 2, 500, 000 - <4, 000, 000 lb, 2022: 2, 2021: 2, 2020: 1, 000 - <2, (1972) 1.0X10+10 G, (1974) 8.17X10+9 G, U.S. Imports: (1972) 8.6X10+8 G, (1975) 1.73X10+9 G, (1984) 9.31X10+9 g, U.S. Exports: (1972) NEGLIGIBLE, 1.68X10+8 g, General Manufacturing Information: Not Known or Reasonably Ascertainable, All Other Chemical Product and Preparation Manufacturing, Photographic Film, Paper, Plate, and Chemical Manufacturing, Plastics Material and Resin Manufacturing, Paint and Coating Manufacturing, All Other Basic Organic Chemical Manufacturing, Miscellaneous Manufacturing, Pesticide, Fertilizer, and Other Agricultural Chemical Manufacturing, Mining (except Oil and Gas) and support activities, Soap, Cleaning Compound, and Toilet Preparation Manufacturing, Ethanedioic acid: ACTIVE, IT IS A PRODUCT OF THE METABOLISM OF MANY MOLDS, SEVERAL SPECIES OF PENICILLIUM & ASPERGILLUS CONVERT SUGAR INTO CALCIUM OXALATE WITH 90% YIELD UNDER OPTIMUM CONDITIONS., BY 1983, MOST USA PRODUCERS, HAD ENDED PRODUCTION AND USA DEMAND HAS BEEN FILLED BY IMPORTS, PRINCIPALLY FROM CHINA AND BRAZIL.
Independent reference data for Oxalic acid (CAS 144-62-7), compiled from public chemistry databases.
| CAS Registry Number | 144-62-7 |
|---|---|
| PubChem CID | 971 |
| Molecular formula | C2H2O4 |
| IUPAC name | oxalic acid |
| UNII (FDA) | 9E7R5L6H31 |
| Molecular Weight | 90.03 |
|---|---|
| XLogP3 | -0.3 |
| Hydrogen Bond Donor Count | 2 |
| Hydrogen Bond Acceptor Count | 4 |
| Rotatable Bond Count | 1 |
| Exact Mass | 89.99530854 |
| Monoisotopic Mass | 89.99530854 |
| Topological Polar Surface Area | 74.6 |
| Heavy Atom Count | 6 |
| Melting Point | 189.5 |
|---|---|
| Melting Point | 189.5 °C (DECOMPOSES) |
| Melting Point | 189.5 °C |
| Melting Point | 372 °F |
| Solubility | 50 to 100 mg/mL at 75 °F (NTP, 1992) |
| Solubility | 220000 |
| Solubility | 220 mg/mL at 25 °C |
| Solubility | 14% |
| Density | 1.90 @ 17 DEG/4 °C, ALPHA |
| Density | 1.9 g/cm³ |
oxalic acid; ethanedioic acid; 144-62-7; Aktisal; Aquisal; Oxiric acid; Kyselina stavelova; Oxaalzuur; Oxalsaeure; Acidum oxalicum; Acide oxalique; Acido ossalico; Ethanedionic acid; NCI-C55209; Ethane-1,2-dioic acid; DTXSID0025816
| Regulatory & Food Contact | FDA Inventory of Food Contact Substances Listed in 21 CFR: FCS |
|---|---|
| GHS notification summary | 0.2% (2 / 1282) |
| GHS notification summary | 0.2% (2 / 1282) |
|---|---|
| Reported hazard statements | H302, H312, H318 (31.1%), H315, H335, H361, H370, H372 |
H302: Harmful if swallowed [Warning Acute toxicity, oral]
H312: Harmful in contact with skin [Warning Acute toxicity, dermal]
Oxalic acid · CAS 144-62-7 · C2H2O4. UNII 9E7R5L6H31. Melting Point: 189.5; Melting Point: 189.5 °C (DECOMPOSES); Melting Point: 189.5 °C.
Source: PubChem / Wikidata; the batch COA governs where values differ.
Supplier: Jinan Shenghe Chemical Co., Ltd.
中文页面: 草酸