Fact-checked by Grok 2 weeks ago

Sodium oxalate

Sodium oxalate, with the chemical formula Na₂C₂O₄, is the disodium salt of oxalic acid, appearing as an odorless white crystalline powder that is highly soluble in water and has a molecular weight of 134.00 g/mol.^[1] This compound serves as a key reducing agent and chelating agent in various applications, including analytical chemistry where it acts as a primary standard for standardizing potassium permanganate solutions in redox titrations due to its precise stoichiometry and stability.^[2]^[1] In industry, sodium oxalate is employed in textile finishing to remove impurities and in leather tanning to facilitate metal complexation.^[1] It also functions as a chelating agent in cosmetics and in laboratory synthesis for various substances.^[1]^[3] Physically, it decomposes at 250–270 °C without melting and has a density of 2.27 g/cm³, forming basic aqueous solutions.^[1]^[3] Regarding safety, sodium oxalate is classified as acutely toxic (Category 4) if swallowed or in contact with skin, potentially causing pain, vomiting, mucosal irritation, and severe kidney damage from oxalate ion accumulation; it is also harmful to aquatic life.^[1]^[3]

Chemical identity and properties

Formula and structure

Sodium oxalate has the molecular formula \ce{Na2C2O4}.^[4] Its molar mass is 133.998 g/mol.^[5] The compound is ionic in nature, consisting of two sodium cations (\ce{Na+}) and one oxalate anion (\ce{C2O4^2-}).^[4] The oxalate anion is the dianion derived from oxalic acid (\ce{(COOH)2}), where the two carboxylic acid groups are deprotonated. In the solid state, sodium oxalate adopts a monoclinic crystal structure with space group P2_1/c. The unit cell parameters at room temperature are a = 10.426(9) Å, b = 5.255(5) Å, c = 3.479(3) Å, and \beta = 92.14(8)^\circ. The systematic IUPAC name for sodium oxalate is disodium ethanedioate.^[4] It is commonly referred to as sodium oxalate, and its CAS Registry Number is 62-76-0.^[4]

Physical and thermodynamic properties

Sodium oxalate is a white, crystalline, odorless solid that sinks and mixes slowly with water.^[1] Its density is 2.27 g/cm³.^[4] The compound exhibits moderate solubility in water, with a value of 3.7 g per 100 mL at 20 °C; this solubility increases with rising temperature, reaching approximately 6.3 g per 100 mL at 100 °C.^[6] It is insoluble in ethanol.^[6] Sodium oxalate does not melt but decomposes upon heating at 250–270 °C.^[3] Key thermodynamic properties include a standard enthalpy of formation (ΔH_f°) of -1318 kJ/mol and a specific heat capacity of 130 J/mol·K at 281 K.^[7]^[8] The solid is slightly hygroscopic, absorbing minimal moisture (about 0.009% by weight over several days in humid air), and remains stable under ambient conditions.^[9]^[10]

Synthesis and production

Laboratory preparation

Sodium oxalate is commonly prepared in the laboratory via the neutralization of oxalic acid with sodium hydroxide in a 1:2 molar ratio, yielding the dihydrate form upon crystallization.^[11] The balanced chemical equation for this acid-base reaction is:

\mathrm{H_2C_2O_4 + 2NaOH \rightarrow Na_2C_2O_4 + 2H_2O}

In a typical procedure, oxalic acid dihydrate is dissolved in a minimal amount of warm distilled water to form a clear solution, followed by the slow addition of a stoichiometric amount of sodium hydroxide solution while stirring and maintaining a slightly elevated temperature to ensure complete reaction.^[11] The resulting solution is then concentrated if necessary and allowed to cool slowly to room temperature or in an ice bath, promoting the precipitation of sodium oxalate crystals due to its reduced solubility in colder water.^[9] The precipitated crystals are collected by vacuum or gravity filtration, washed with cold distilled water or ethanol to remove impurities, and dried in an oven at around 100–110°C to obtain the anhydrous salt or controlled humidity for the dihydrate.^[9] Yields in this method often exceed 90%, approaching theoretical values near 99% with precise stoichiometry and minimal losses during isolation.^[11] An alternative laboratory method involves the reaction of sodium carbonate with oxalic acid, which proceeds with effervescence due to carbon dioxide evolution:

\mathrm{Na_2CO_3 + H_2C_2O_4 \rightarrow Na_2C_2O_4 + H_2O + CO_2}

This approach, historically used in early 20th-century preparations, similarly involves dissolving the reactants in water, heating gently to complete the reaction, and isolating the product via cooling, filtration, washing, and drying.^[12]^[13] For high purity, especially when sodium oxalate is intended as a primary standard, the crude product is purified by recrystallization from hot water, dissolving the salt in the minimum volume of boiling water, filtering hot to remove insolubles, and cooling to recrystallize, followed by drying at 240°C to eliminate water of hydration and volatile impurities.^[9] This step ensures analytical-grade material with minimal hydrolyzable impurities, as emphasized in seminal work by Sørensen in 1897 for volumetric standardization.^[12]

Industrial production

Sodium oxalate is produced on an industrial scale through several methods, including the neutralization of oxalic acid with sodium hydroxide. Oxalic acid and caustic soda serve as key raw materials in this process, which is straightforward and widely used for large-scale synthesis.^[14] It is also primarily produced through the thermal decomposition of sodium formate at temperatures above 360 °C, following the reaction:

$2 \ce{HCOONa} \rightarrow \ce{Na2C2O4} + \ce{H2}

This process is typically catalyzed by basic compounds such as sodium hydroxide or sodium carbonate, which improve the yield and selectivity toward sodium oxalate while minimizing side products like sodium carbonate.^[15] The reaction occurs in specialized reactors designed to handle the high temperatures and gaseous hydrogen byproduct, making it a cost-effective method for large-volume synthesis.^[16] A substantial amount of sodium oxalate is also obtained as a recoverable byproduct from waste streams generated during ethylene glycol production, particularly in routes involving oxalate esters and subsequent hydrogenation steps used in polyester manufacturing. These waste crystalline salts, which contain sodium oxalate, are treated to extract and purify the compound, contributing to resource efficiency and reducing disposal needs.^[17] Following synthesis or recovery, the crude sodium oxalate dihydrate is purified to the anhydrous form via vacuum drying or calcination at 200–250 °C, which removes bound water without significant decomposition. This step ensures high purity suitable for industrial applications, with careful control of heating rates to avoid oxalate breakdown.^[18] Global production of sodium oxalate is dominated by China, which accounts for over 70% of the world's output, with total annual capacity exceeding 150,000 metric tons as of 2023. Major producers in China leverage the formate decomposition route and byproduct recovery to meet demand from sectors like chemical manufacturing and metal processing.^[19]^[20] Environmental considerations in sodium oxalate production include managing process effluents to mitigate potential ecological impacts from oxalate ions, such as precipitation with metals and toxicity in aquatic environments.

Chemical reactions and reactivity

Reactions in aqueous solutions

When dissolved in water, sodium oxalate undergoes complete ionization to yield two sodium cations (Na⁺) and one oxalate anion (C₂O₄²⁻) per formula unit, as expected for this ionic salt. The oxalate anion is highly hydrated in solution, forming a fragile solvation sheath that diminishes with increasing solute concentration, while sodium oxalate also forms double-solvent-separated ion pairs at higher concentrations with an association constant of K_A = 1.04 ± 0.02 at infinite dilution.^[21]^[22] The behavior of oxalate in aqueous solution is pH-dependent due to its hydrolysis. At neutral or basic pH, the oxalate anion (C₂O₄²⁻) predominates, but in more acidic conditions, it protonates to form hydrogen oxalate (HC₂O₄⁻) via the equilibrium C₂O₄²⁻ + H⁺ ⇌ HC₂O₄⁻, governed by the second dissociation constant of oxalic acid (pK_a2 = 4.28 at 25 °C). This hydrolysis influences the availability of free oxalate for subsequent reactions, with significant protonation occurring below pH 5.^[23]^[24] Oxalate ions readily form chelate complexes with divalent and trivalent metal cations, such as Ca²⁺ and Fe³⁺, often leading to the precipitation of insoluble metal oxalates. For instance, calcium oxalate (CaC₂O₄) is sparingly soluble, with a solubility product constant K_{sp} = 2.7 × 10^{-9} at 25 °C, which underscores its tendency to precipitate in the presence of Ca²⁺. The stability of the aqueous Ca²⁺-oxalate complex is characterized by a formation constant log β_1 = 3.00 (at zero ionic strength), indicating moderate complexation strength. Similarly, Fe³⁺ forms stable chelates like the ferrioxalate complex [Fe(C₂O₄)_3]^{3-}, though these can contribute to insoluble phases under certain conditions.^[25]^[26]^[27] A prominent redox reaction involving oxalate in acidic aqueous solution is its use in standardizing permanganate titrants. The balanced equation for the oxidation of oxalate by permanganate is:

$5 \text{C}_2\text{O}_4^{2-} + 2 \text{MnO}_4^- + 16 \text{H}^+ \rightarrow 10 \text{CO}_2 + 2 \text{Mn}^{2+} + 8 \text{H}_2\text{O}

This reaction proceeds slowly at room temperature but accelerates significantly when heated to 55–60 °C, allowing for accurate volumetric analysis where 5 moles of oxalate react with 2 moles of permanganate.^[28]^[29]

Thermal and oxidative decomposition

Sodium oxalate undergoes thermal decomposition above 290 °C, primarily following the reaction \ce{Na2C2O4 -> [Na2CO3](/page/Sodium_carbonate) + [CO](/page/Carbon_monoxide)}, yielding sodium carbonate and carbon monoxide as products. This solid-state process initiates with dehydration if the monohydrate form is present, followed by decarboxylation, and completes between 750 °C and 800 °C within approximately 20 minutes, leaving sodium carbonate as the stable residue.^[18] The decomposition temperature and pathway can vary slightly with particle size, doping, or pre-treatment, but the primary stoichiometry remains consistent under inert atmospheres.^[30] In oxidative conditions, such as exposure to air, the evolved carbon monoxide undergoes further oxidation to carbon dioxide, resulting in the overall balanced equation \ce{2 Na2C2O4 + [O2](/page/O2) -> 2 Na2CO3 + 2 CO2}.^[31] This enhanced conversion ensures complete mineralization to carbonate without residual carbon monoxide under sufficient oxygen availability, often observed in open-air heating experiments.^[32] The kinetics of thermal decomposition exhibit a two-step mechanism involving initial formation of an oxalate radical intermediate, with an apparent activation energy of approximately 150 kJ/mol determined via non-isothermal methods like Ozawa-Flynn-Wall and Kissinger-Akahira-Sunose approaches.^[30] Rate constants decrease with dopants like aluminum or phosphate, indicating catalytic inhibition, while pre-compression of samples can alter the decomposition rate by modifying crystal defects.^[33] Controlled thermal decomposition serves as a basis for gravimetric analysis of oxalate content, where samples are heated to convert \ce{Na2C2O4} quantitatively to \ce{Na2CO3}, allowing determination of oxalate mass from the observed weight loss due to CO evolution.^[34] This method provides precise quantification in analytical contexts, leveraging the stoichiometric 21% mass loss from the reaction. Decomposition evolves toxic carbon monoxide gas, necessitating well-ventilated environments, fume hoods, and monitoring during heating to mitigate inhalation risks, as CO binds strongly to hemoglobin and can cause asphyxiation.^[35]

Applications and uses

Analytical and laboratory applications

Sodium oxalate serves as a primary standard for the standardization of potassium permanganate (KMnO₄) solutions in redox titrations due to its high purity, thermal stability, and non-hygroscopic properties.^[9] In this procedure, a weighed sample of sodium oxalate is dissolved in dilute sulfuric acid and titrated with KMnO₄ at 25–30°C, where the oxalate ion is oxidized to carbon dioxide according to the stoichiometry involving five equivalents of oxalate per two equivalents of permanganate, yielding an exact equivalent weight of 67 g/equiv.^[29] The endpoint is indicated by the persistent pink color of excess permanganate, enabling precise determination of KMnO₄ concentration with uncertainties typically below 0.1%.^[36] This method, rooted in 19th-century advancements in volumetric analysis, provides a reliable alternative to other standards like oxalic acid, avoiding issues with volatility or hygroscopicity.^[9] In gravimetric analysis, sodium oxalate is employed to precipitate calcium ions as calcium oxalate monohydrate (CaC₂O₄·H₂O) from aqueous solutions, particularly in samples like milk or environmental matrices where sodium interference is minimal.^[37] The procedure involves adding excess sodium oxalate to an alkaline or neutral solution containing calcium, forming the insoluble precipitate, which is then filtered, washed, dried at 105°C, and weighed to calculate calcium content based on the known stoichiometry (1:1 molar ratio of Ca to C₂O₄). This technique offers high accuracy for calcium quantification in the range of 0.1–10% by weight, with recovery rates exceeding 99% under controlled pH conditions (typically 5–10).^[38]^[39] Beyond titrations and precipitations, sodium oxalate finds use as a calibration standard in ion chromatography for quantifying oxalate ions in complex matrices such as urine or industrial liquors.^[40] Standards prepared from high-purity sodium oxalate (e.g., 1000 mg/L solutions) enable linear calibration curves with correlation coefficients >0.999, facilitating detection limits as low as 0.1 mg/L using suppressed conductivity detection.^[41] Additionally, it acts as a component in buffer systems for oxalate-based enzymatic assays, where mixtures of sodium oxalate and oxalic acid maintain pH around 4.0, stabilizing enzyme activity during kinetic studies of oxalate decarboxylase or oxidoreductase.^[42] These applications leverage its solubility (3.7 g/100 mL at 20°C) and defined oxalate content for reproducible results in routine laboratory testing.^[43]

Industrial and commercial uses

Sodium oxalate serves as an exhausting agent in the reactive dyeing of cotton fabrics, enhancing dye uptake and fixation to improve colorfastness by forming complexes with metal salts used in the process.^[44] In textile finishing, it acts as a chelating agent to remove impurities, rust, and ink stains from fabrics, contributing to better texture and dye absorption while aiding in bleaching operations for cotton and other materials.^[45]^[46] These applications leverage its ability to bind metal ions, promoting color stability in industrial-scale production. In photography, sodium oxalate is employed in certain developer formulations for platinum and palladium printing processes, where it supports reduction reactions necessary for image formation.^[47] As a precipitating and stripping agent, sodium oxalate plays a key role in rare earth element extraction, where it selectively forms insoluble oxalates with elements such as neodymium and thorium from acidic solutions, facilitating their separation at low pH levels around 1.5.^[48]^[49] This method simplifies downstream processing by combining precipitation, saponification, and metal recovery in hydrometallurgical operations. Additionally, its mild reducing properties, derived from oxalate ions, aid in cleaning metal surfaces by chelating and removing rust, tarnish, and mineral deposits from materials like stainless steel, aluminum, and iron, often in formulations that accelerate rust dissolution without excessive corrosion.^[50]^[51]^[52] In water treatment, sodium oxalate functions as a sequestrant for heavy metals in wastewater, binding ions such as mercury, copper, and lead to prevent their redeposition and enable removal through precipitation or filtration, thereby improving effluent quality in industrial settings.^[53]^[54] Recent developments since 2020 have expanded sodium oxalate's role in lithium-ion battery production, where it serves as an oxalate precursor in co-precipitation methods to synthesize uniform cathode materials like nickel-manganese-cobalt (NMC) oxalates, which are calcined to form layered oxides for high-energy-density cells.^[55]^[56] This approach enhances precursor morphology and electrochemical performance, supporting sustainable recycling and manufacturing of battery components. The global market for sodium oxalate reflects steady demand, with annual production exceeding 150,000 metric tons as of 2024, driven by applications in chemicals, metals, and emerging technologies; pricing has shown moderate upward trends due to raw material costs and supply chain factors, averaging fluctuations of 5-10% annually in recent years.^[19]^[57]

Biological and toxicological aspects

Biological activity and mechanisms

Sodium oxalate exhibits anticoagulant properties primarily through its ability to chelate calcium ions (Ca²⁺), which are essential cofactors in the blood coagulation cascade. By forming insoluble calcium oxalate complexes, it sequesters free Ca²⁺, thereby inhibiting calcium-dependent steps such as the activation of factor X and the formation of the prothrombinase complex, preventing fibrin clot formation in collected blood samples.^[58]^[59] This mechanism is analogous to its interaction with metal ions in aqueous solutions, where oxalate forms stable chelates.^[60] In biological systems, the oxalate ion from sodium oxalate can inhibit enzymes like lactate dehydrogenase (LDH) through competitive mimicry. Oxalate structurally resembles the substrate lactate and binds to the enzyme's active site, particularly competing with lactate in the LDH-catalyzed conversion of lactate to pyruvate, with inhibition observed at concentrations as low as 0.2 mM, reducing LDH activity by 55-68% in serum samples.^[61]^[62] This inhibition disrupts glycolytic pathways and has implications for metabolic regulation, as LDH plays a key role in anaerobic energy production. In plants, oxalate, including forms derived from sodium oxalate in certain contexts, occurs naturally in high concentrations in species like rhubarb (Rheum rhabarbarum) and sorrel (Rumex acetosa), where it contributes to mineral regulation by binding calcium to form crystals that aid in calcium homeostasis and detoxification of excess metals.^[63]^[64] These calcium oxalate crystals help regulate intracellular pH, protect against herbivory, and support tissue development without disrupting essential mineral availability.^[65] Pharmacokinetically, sodium oxalate dissociates into oxalate ions upon ingestion or administration, which are rapidly absorbed in the upper gastrointestinal tract via paracellular and transcellular pathways, with absorption rates typically ranging from 2-15% depending on dietary factors and gut conditions.^[66] Once absorbed, oxalate is not significantly metabolized further in humans but circulates systemically before primarily renal excretion, though it can form insoluble salts with minerals like calcium.^[67]^[68]

Toxicity, safety, and handling

Sodium oxalate exhibits moderate acute toxicity upon ingestion, with an oral LD50 of approximately 11.16 g/kg in rats.^[69] Acute exposure primarily affects the gastrointestinal system, causing symptoms such as severe pain, vomiting, and potentially hypocalcemia due to the compound's ability to chelate calcium ions.^[1] Inhalation of sodium oxalate dust can irritate the respiratory tract, leading to coughing and shortness of breath, while skin contact with concentrated solutions may cause irritation, redness, or burns upon prolonged exposure.^[70] Eye contact should be avoided, as it can result in irritation or corneal damage.^[71] Chronic exposure to sodium oxalate is associated with kidney damage, primarily through the formation of insoluble calcium oxalate crystals that precipitate in the renal tubules, leading to nephrolithiasis and potential progression to chronic kidney disease.^[72] Repeated low-level ingestion or absorption can exacerbate this by promoting hyperoxaluria and tubulointerstitial injury.^[73] Regulatory exposure limits for sodium oxalate, treated as a particulate not otherwise classified, include an OSHA permissible exposure limit (PEL) of 5 mg/m³ as an 8-hour time-weighted average for respirable dust. The International Agency for Research on Cancer (IARC) does not classify sodium oxalate as carcinogenic to humans.^[70] Safe handling requires the use of personal protective equipment (PPE), including gloves, safety goggles, and respiratory protection in dusty environments to minimize exposure.^[10] Sodium oxalate should be stored in a cool, dry place in tightly sealed containers to prevent moisture absorption and decomposition.^[45] For first aid, in cases of ingestion, administer milk or calcium gluconate to bind oxalate ions and seek immediate medical attention; for inhalation or skin contact, move to fresh air or rinse affected areas with water.^[1] Environmentally, sodium oxalate is considered biodegradable through natural microbial processes but poses risks to aquatic life, with potential for acute toxicity to fish and invertebrates at concentrations above 100 mg/L, necessitating proper disposal to avoid release into waterways.^[3]

References

[1]
Sodium Oxalate | Na2C2O4 | CID 6125 - PubChem
Sodium oxalate is an organic sodium salt consisting of sodium and oxalate ions in a 2:1 ratio. It has a role as a poison and a reducing agent.
[2]
[PDF] Standardization of potassium permanganate solution by sodium ...
The sodium oxalate used for all of the experiments except those of Table IV, b, was a sample specially purified in this laboratory by Mr. J. B. Tuttle. It ...Missing: industry | Show results with:industry
[3]
Solubility of sodium oxalate in kraft black liquors above 100 °C
Nov 23, 2022 · The solubility of sodium oxalate was measured in kraft black liquors at temperatures of 115 °C to 140 °C with dry solid contents of 45% to 70%.
[4]
https://pubchem.ncbi.nlm.nih.gov/compound/6125
[5]
https://webbook.nist.gov/cgi/cbook.cgi?ID=C62760
[6]
Sodium oxalate
### Summary of Thermodynamic Data for Sodium Oxalate
[7]
Sodium oxalate | 62-76-0 - ChemicalBook
Sep 18, 2025 · CAS No. 62-76-0 ; Chemical Name: Sodium oxalate ; CBNumber: CB5369366 ; Molecular Formula: C2Na2O4 ; Molecular Weight: 134.Missing: mass | Show results with:mass
[8]
Sodium oxalate, 98.5%, extra pure 100 g - Fisher Scientific
4–8 day delivery 30-day returnsSolubility Information, Solubility in water: 37g/L (20°C). Other solubilities: 6.3g/100mL water (100°C),insoluble in ethanol and ether ; Formula Weight, 134.
[9]
Investigation on the drying and decomposition of sodium oxalate
The decomposition begins at 290 degrees and heating between 200 degrees and 250 degrees is recommended for the dehydration of sodium oxalate.
[10]
Na2C2O4 properties
The standard enthalpy of formation measures -1318 kJ/mol, while the standard Gibbs free energy of formation is -1209 kJ/mol. The entropy of formation stands at ...
[11]
Sodium oxalate - the NIST WebBook
Sodium oxalate has the formula C2Na2O4, molecular weight of 133.9985, and is also known as Ethanedioic acid, disodium salt.
[12]
[PDF] sodium oxalate as a standard in volumetric analysis
2. HYGROSCOPIC PROPERTIES. Sorensen 7 found that 10 g of his sodium oxalate absorbed only. 0.0009 g (0.009 per cent)of water when exposed for three days to.
[13]
[PDF] Sodium Oxalate - SAFETY DATA SHEET
May 8, 2014 · Precautionary Statements. Prevention. Wash face, hands and any exposed skin thoroughly after handling. Do not eat, drink or smoke when using ...
[14]
Sodium oxalate synthesis - ChemicalBook
Sodium oxalate can be prepared through the neutralization of oxalic acid with sodium hydroxide (NaOH) in a 1:2 acid-to-base molar ratio.Missing: lab | Show results with:lab
[15]
[PDF] The hydrolysis of sodium oxalate and its influence upon the test for ...
such excess "carbonic acid." When we consider that as usuaDy prepared (by neutralization of oxalic acid with sodium carbonate) the salt separates from a ...
[16]
Na2CO3 + H2C2O4 = Na2C2O4 + CO2 + H2O - Chemical Equation ...
Word Equation. Sodium Carbonate + Oxalic Acid = Sodium Oxalate + Carbon Dioxide + Water. One mole of Sodium Carbonate [Na2CO3] and one mole of Oxalic Acid ...
[17]
The thermal decomposition of HCOONa in presence of NaOH
The solid products of the thermal decomposition of sodium formate there are sodium carbonate and sodium oxalate: As the last-mentioned product usually is ...
[18]
Technology of producing sodium oxalate by sodium formate spray ...
Sodium formate spray dehydrogenation process to produce sodium oxalate, (1) Superheated steam with a temperature of about 500°C and solid sodium formate at ...Missing: thermal | Show results with:thermal
[19]
CN111762801A - Method for treating waste crystalline salt obtained ...
... waste caused by landfill disposal ... The waste crystallized salt for the production of ethylene glycol ... sodium oxalate in the waste crystallized salt. 7 ...
[20]
Sodium Oxalate 2025-2033 Trends: Unveiling Growth Opportunities ...
Rating 4.8 (1,980) Mar 25, 2025 · World Sodium Oxalate Production: Annual global production is estimated at over 150 million kilograms, with production capacity heavily ...Missing: output | Show results with:output
[21]
Sodium Oxalate Supplier Guide: Evaluate Top Chinese ...
With China dominating global production—accounting for over 70% of the world's output—strategic procurement requires not just access to suppliers, but a deep ...
[22]
Removal routes of hazardous sodium oxalate in the alumina ...
As a key organic impurity in Bayer process, sodium oxalate seriously affects the quality of alumina products, thereby threatening the effective utilization ...
[23]
Hydration and Ion Pairing in Aqueous Sodium Oxalate Solutions
Apr 9, 2003 · Detailed analysis of the solvent dispersion amplitude indicates that the oxalate ion is highly hydrated but that its solvation sheath is “ ...Missing: source | Show results with:source
[24]
Hydration and ion pairing in aqueous sodium oxalate solutions
Detailed analysis of the solvent dispersion amplitude indicates that the oxalate ion is highly hydrated but that its solvation sheath is "fragile", decreasing ...
[25]
Oxalic Acid | (COOH)2 | CID 971 - PubChem - NIH
6 Solubility. 50 to 100 mg/mL at 75 °F (NTP, 1992).
[26]
Solubility and pH
... acid (pK a1 = 1.23 and pK a2 = 4.19). Consequently, the oxalate ion has a significant affinity for one proton and a lower affinity for a second proton.
[27]
Ksp Table
Solubility Product Constants near 25 °C. Ionic Compound Formula Ksp. Aluminum ... Calcium oxalate CaC2O4 2.7×10–9. Calcium phosphate Ca3(PO4)2 2.0×10–29.Missing: log | Show results with:log
[28]
[PDF] Oxalate metal complexes in aerosol particles - ACP
Stability constant (log K) of oxalate with some metal ions at 25 ◦C ... From their stability constants, Ca ion is the dominant divalent metal ion in ...
[29]
Fe(III)-Oxalate complex photolysis and ROS generation
Results showed that Fe(III)-Ox complex with MB binding geometry was formed on ferridydrite, which was inclined to dissolve into solution first, followed by ...
[30]
[PDF] Standardization of potassium permanganate titrant
Feb 3, 2022 · As the reaction shown in formula (1), 2 mol of potassium permanganate is quantitatively reacted with 5 mol of sodium oxalate, and an inflection ...
[31]
[PDF] Standardization of permanganate solutions with sodium oxalate
In the recommended procedure, 90 to 95 percent of the permanganate is added rapidly to a diluted sulphuric acid (5+95) solution of sodium oxalate at 25 to 30° C ...
[32]
Non-isothermal kinetics of the thermal decomposition of sodium ...
Jun 3, 2011 · The kinetics of thermal decomposition of Na2C2O4 under non-isothermal heating was studied using the Ozawa and KAS methods. The results obtained ...
[33]
https://ui.adsabs.harvard.edu/abs/2012TcAc..534...64J/abstract
[34]
Kinetic studies on the thermal decomposition of aluminium doped ...
The kinetics of thermal decomposition of sodium oxalate (Na2C2O4) has been studied as a function of concentration of dopant, aluminium, at five different ...Missing: air | Show results with:air
[35]
Kinetic studies on the thermal decomposition of aluminium doped ...
The kinetics of thermal decomposition of sodium oxalate (Na 2C 2O 4) has been studied as a function of concentration of dopant, aluminium, at five different ...
[36]
Investigation on the drying and decomposition of sodium oxalate
The decomposition begins at 290° and heating between 200° and 250° is recommended for the dehydration of sodium oxalate. The decomposition is complete between ...Missing: oxidative | Show results with:oxidative
[37]
[PDF] Safety Data Sheet: di-Sodium oxalate - Carl ROTH
The times are approximate values from measurements at 22 ° C and permanent contact. Increased temperatures due to heated substances, body heat etc. and a ...
[38]
Potassium Permanganate | ACS Reagent Chemicals
Feb 28, 2017 · Weigh accurately about 0.25 g of NIST SRM or primary standard sodium oxalate (dried at 105 °C), and dissolve in a 500 mL glass-stoppered flask.
[39]
TUTORIAL CHAPTER 6GRAVIMETRIC ANALYSIS (pdf) - CliffsNotes
200g sample of milk was added with excess aqueous sodium oxalate until precipitate was formed. If the precipitate of calcium oxalate formed was 0.65 g, find the ...<|control11|><|separator|>
[40]
[PDF] Experiments - the Chem Connections Homepage
Gravimetric Determination of Calcium as CaC2O4.H2O12. Calcium ion can be ... Dry sodium oxalate (Na2C2O4) at 105˚C for 1 h, cool in a desiccator, and ...
[41]
[PDF] AN 206: Determination of Oxalate and Other Anions in Bayer Liquor ...
Ion chromatography (IC) is used to determine oxalate and other anions in Bayer liquor, which is important because oxalate can interfere with crystal formation.
[42]
[PDF] Determination of oxalate in cromolyn sodium - Thermo Fisher Scientific
To develop an ion chromatography (IC) method for the determination of oxalate in cromolyn sodium using a. Reagent-Free™ Ion Chromatography (RFIC™) system with.
[43]
Calibration functions of the different buffer/indicator systems used as...
Reagents: Re0, 0.2 M sodium oxalate/0.035 mM Methyl Red; Re1–0.18 M sodium ... This auxiliary buffer would neutralize the sample acidity and maintain the preset ...
[44]
Analytical procedures and methods validation for oxalate content ...
The method of oxalate estimation by titration with NaOH is based on oxalic acid reaction with NaOH, while bacteria may produce other different organic acids ...
[45]
Application of sodium oxalate in the dyeing of cotton fabric with ...
The overall results suggested that sodium oxalate has the potential not only as an exhausting agent for reactive dyeing of cotton but also as an accelerant for ...
[46]
https://vinipulchemicals.com/sodium-oxalate-suppliers
[47]
Sodium Oxalate suppliers – manufacturers - Vinipul Chemicals Pvt. Ltd
Specifications ; Physical Appearance, Odourless white solid. ; pH, 8 (30 g/l, H₂O, 20 °C) ; Solubility, soluble in formic acid insoluble in alcohol, ether.
[48]
Sodium Oxalate - Nanyang Chemical
Sodium oxalate is a chemical compound composed of sodium ions and oxalate ions. ... Metal Finishing: Used in metal cleaning and surface preparation. Photography ...
[49]
Neodymium naphthenate-loaded organic phase stripping using ...
Sodium oxalate can serve as a stripping agent, a saponifier, and a precipitator, thereby simplifying rare earth extraction and separation.
[50]
Methods for the extraction of minerals with rare earths
To recover thorium and rare earths from the solution, the acidic solution is treated with sodium oxalate, precipitating thorium and rare earths at pH 1.5, ...
[51]
Green Approach for Rare Earth Element (REE) Recovery from Coal ...
Herein, we demonstrate that oxalate can be directly added to the leachate containing coexisting Ca2+ to selectively separate REEs over interfering metal ions ...
[52]
The Chemistry of Clean: Utilizing Sodium Oxalate for Effective Metal ...
Oct 13, 2025 · Learn how Sodium Oxalate excels in metal surface treatment for rust removal and decontamination, providing a clean and protected finish.
[53]
US2832706A - Metal cleaning and phosphating composition and ...
The sodium oxalate component of the new composition acts as an accelerator for both the removal of rust and improvement of the phosphatizing action, and does ...
[54]
Sodium Oxalate - Bluestone Products – Specialty Metals & Chemicals
Sodium Oxalate is an important chemical used as a reducing agent in various industrial processes, including metal refining.
[55]
Extraction Heavy Metals from Contaminated, Water using Chelating ...
The results showed that the extraction ability for mercury and copper from the polluted water decreased as follows: OA > CA > EDTA.
[56]
(PDF) The Effect of Lithium Excess on NMC-721 using Oxalate Co ...
Aug 6, 2025 · It can be concluded that the NMC-721 were successfully synthesized and can be applied for lithium-ion battery.
[57]
[PDF] Re-synthesis of Cathode Precursors from End-of-Life Lithium- Ion ...
Mar 31, 2025 · In this study, two different leach liquors and one synthetic solution were used for precursor production via oxalate precipitation. The ...Missing: sodium | Show results with:sodium
[58]
Exploring the Dynamics of Sodium Oxalate: Key Insights and Trends ...
Oct 15, 2025 · Pricing Shifts: Fluctuations in raw material prices, energy costs, and transportation influence the final price of sodium oxalate. Supply chain ...Missing: annual | Show results with:annual
[59]
Laboratory Tube Collection - StatPearls - NCBI Bookshelf - NIH
The grey tubes contain potassium oxalate that binds to calcium, thus, inhibiting coagulation. Another substance, sodium fluoride, is also contained in the ...Missing: properties | Show results with:properties
[60]
Global assays and the management of oral anticoagulation - PMC
The prothrombin time assay introduced by Quick was performed in plasma taken from blood collected into sodium oxalate and clotting was initiated by adding ...
[61]
Clot activators and anticoagulant additives for blood collection. A ...
Heparin potentiates antithrombin and hirudin binds to active thrombin, inactivating the thrombin irreversibly.
[62]
Urea and oxalate inhibition of the serum lactate dehydrogenase - PMC
The serum lactate dehydrogenase (LDH) of 16 normal subjects was inhibited by 55 to 68% by the incorporation into the reaction mixture of 0·2 mM-oxalate.
[63]
Urea and oxalate inhibition of the serum lactate dehydrogenase
The serum lactate dehydrogenase (LDH) of 16 normal subjects was inhibited by 55 to 68% by the incorporation into the reaction mixture of 0.2 mM-oxalate.
[64]
Oxalate in Foods: Extraction Conditions, Analytical Methods ... - NIH
In plants, it plays a relevant role in various functions such as calcium homeostasis; pH regulation; plant growth, development and protection; photosynthesis; ...
[65]
Update on Oxalate Crystal Disease - PMC - NIH
Rarely, ingestion of large amounts of oxalate-rich foods such as rhubarb, star fruit or sorrel soup have been associated with acute kidney injury due to calcium ...
[66]
Effects of processing on oxalate contents in plant foods: A review
High intake of soluble oxalate from the diet can increase the risk of kidney stone formation as well as mineral deficiency and restriction of dietary oxalate ...
[67]
Dietary oxalate and kidney stone formation
Oxalate is absorbed by both para- and transcellular mechanisms, and their relative contributions may vary in different intestinal segments (14). SLC26 ...Abstract · Oxalate Degradation By Gut... · Future Directions
[68]
Urinary oxalic acid excretion differs after oral loading of rats with ...
The upper gastrointestinal tract seems to be the major site of oxalic acid absorption and only free oxalate is absorbed irrespective of whether it is the ...
[69]
Sodium Chloride-Dependent Oxalate Absorption in the Human Gut
We investigated the effect of sodium chloride intake on oxalate and calcium metabolism in the human body.Missing: biological activity
[70]
[PDF] Safety Data Sheet - Fisher Scientific
Mar 19, 2015 · Carbon oxides. Acute Toxicity: Oral: 62-76-0 (Sodium oxalate) LD50 Rat: 11,160 mg/kg Chronic Toxicity: No additional information.Missing: CO | Show results with:CO
[71]
[PDF] SAFETY DATA SHEET
Oct 26, 2020 · Eye Contact: Depending on concentration and duration of exposure, sodium oxalate dust may cause eye irritation with redness and pain. Repeated ...
[72]
https://pmc.ncbi.nlm.nih.gov/articles/PMC8431202/
[73]
A Sodium Oxalate-Rich Diet Induces Chronic Kidney Disease ... - NIH
Aug 26, 2021 · It has been shown that a diet rich in sodium oxalate induces stable CKD in mice, as well as related hypertension and cardiac fibrosis [12].
[74]
Sodium Oxalate-Induced Acute Kidney Injury Associated ... - Frontiers
Aug 24, 2020 · Furthermore, NaOx treatment resulted in tubulointerstitial injury, which was confirmed by tubular dilation, albuminuria, increased Kim-1 and ...