Potassium Binoxalate (Potassium Hydrogen Oxalate) CAS 127-95-7
Potassium binoxalate (CAS 127-95-7), also known as potassium hydrogen oxalate, potassium acid oxalate, or potassium bioxalate, is a white crystalline powder widely used as an acidic reducing agent, chelating compound, and specialized cleaning reagent.
Potassium binoxalate, more precisely called potassium hydrogen oxalate, is the monopotassium salt of oxalic acid. It is an acidic oxalate supplied as white or colorless crystals or a white crystalline powder.
Its chemical formula is KHC₂O₄, its CAS number is 127-95-7, and its molecular weight is 128.13 g/mol for the anhydrous substance. Because it provides both acidity and oxalate complexing behavior, potassium binoxalate is used in selected metal surface-treatment, laboratory, textile, cleaning and chemical-processing applications.
Commercial names are not always used consistently. Buyers should therefore confirm the CAS number, molecular formula, hydration state and assay basis before placing an order.
Potassium Binoxalate Quick Facts
Property
Information
Product name
Potassium Binoxalate
Preferred chemical name
Potassium Hydrogen Oxalate
Alternative names
Potassium Acid Oxalate; Oxalic Acid Monopotassium Salt
CAS number
127-95-7
EC number
204-873-0
Molecular formula
KHC₂O₄
Molecular weight
128.13 g/mol for the anhydrous substance
Appearance
White or colorless crystals; white crystalline powder
Odor
Odorless
Chemical type
Acidic potassium salt of oxalic acid
Typical assay
Grade-dependent; commonly 99.0% minimum
Water solubility
Slightly soluble in cold water and more soluble in hot water
Solution character
Acidic
Typical applications
Metal treatment, analytical reagents, textile processing, professional cleaning formulations and chemical processing
The information above describes potassium hydrogen oxalate with CAS 127-95-7. The contracted specification and batch Certificate of Analysis should always take priority over general reference data.
Is Potassium Binoxalate the Same as Potassium Hydrogen Oxalate?
Yes. Potassium binoxalate and potassium hydrogen oxalate normally refer to the same compound: KHC₂O₄, CAS 127-95-7.
The word “binoxalate” is a traditional commercial name. “Potassium hydrogen oxalate” more clearly describes the chemical composition and is less likely to be confused with other potassium oxalates.
Potassium Binoxalate vs Potassium Oxalate and Potassium Tetroxalate
These materials are related but are not interchangeable.
Product
Representative formula
Key characteristic
Potassium binoxalate
KHC₂O₄
Acidic 1:1 potassium salt of oxalic acid
Potassium oxalate
K₂C₂O₄
Fully neutralized dipotassium oxalate
Potassium tetroxalate dihydrate
KH₃(C₂O₄)₂·2H₂O
More highly acidic double oxalate commonly associated with pH-reference applications
Potassium tetroxalate dihydrate is commonly identified by CAS 6100-20-5 and has a molecular weight of approximately 254.19 g/mol. It should not be supplied in place of potassium binoxalate merely because the two products have similar commercial names.
A purchase order should state at least:
Potassium hydrogen oxalate or potassium binoxalate
CAS 127-95-7
Required molecular formula or hydration state
Minimum assay
Required impurity limits
Intended application
Why Does the Hydration State Matter?
The molecular weight of 128.13 g/mol applies to anhydrous KHC₂O₄. Some commercial documents may describe a hydrated form, including material represented as KHC₂O₄·H₂O.
A monohydrate would have a theoretical molecular weight of approximately 146.14 g/mol. If assay calculations, solution concentrations or dosing instructions are based on the wrong hydration state, the actual amount of active potassium hydrogen oxalate can be incorrect.
Before qualification, buyers should verify:
Exact molecular formula
Anhydrous or hydrated form
Assay calculation basis
Moisture or loss-on-drying method
Molecular weight used in solution calculations
Product identity shown on the SDS and COA
Typical Potassium Binoxalate Specifications
The following table presents reference purchasing parameters rather than a universal AOZUN specification. Final limits should be confirmed in the applicable Technical Data Sheet, quotation and sales contract.
Test item
Reference purchasing target
Appearance
White crystals or white crystalline powder
Identification
Conforms
Assay
≥99.0%
Water-insoluble matter
≤0.01–0.05%
Chloride
Grade-dependent; reagent-grade target may be ≤0.005%
Sulfate
Grade-dependent; reagent-grade target may be ≤0.01%
Iron
Grade-dependent; reagent-grade target may be ≤0.002%
Heavy metals
Buyer- and application-specific
Moisture or loss on drying
As agreed for the declared hydration state
Particle size
As agreed
Solution clarity
Clear or within the agreed limit
pH
Tested at a stated concentration and temperature
Different applications require different limits. A metal-treatment process may emphasize assay, insoluble matter, iron and particle size, while an analytical laboratory may require tighter trace-impurity limits and documented test methods.
What Do the Main Quality Parameters Mean?
Assay
Assay indicates the measured potassium hydrogen oxalate content. Buyers should confirm whether the result is reported on an as-is, dried or anhydrous basis.
Water-Insoluble Matter
Low insoluble matter supports cleaner solution preparation and helps reduce sediment, blocked filters and visible residue.
Chloride and Sulfate
Chloride and sulfate limits can be important in metal processing, laboratory analysis and other applications sensitive to ionic contamination.
Iron and Heavy Metals
Trace metals may affect color, analytical results, surface quality or downstream reactions. The required limits should be based on the actual process rather than on a generic supplier specification.
Moisture or Loss on Drying
This test helps verify consistency and is especially important when distinguishing anhydrous material from a hydrated commercial form.
Particle Size
Particle size influences dissolution rate, dust generation, feeding behavior and blending uniformity. Buyers should specify whether they require crystals, fine powder or a controlled particle-size range.
How Does Potassium Binoxalate Work?
Potassium binoxalate combines an acidic hydrogen oxalate ion with potassium. In aqueous systems, its acidity can assist in loosening certain mineral residues, while oxalate ions can interact with selected metal ions. This combination explains its use in controlled analytical, cleaning and metal surface-treatment systems.
Why Water Quality and Surface Conditions Matter
Performance is affected by concentration, temperature, contact time, agitation, water hardness and the composition of the treated surface.
Oxalate can also interact with calcium and other multivalent ions. Hard water may therefore produce unwanted precipitation or reduce consistency. Laboratory trials should use the same water quality, substrate and operating conditions expected in production.
For metal applications, users should verify:
Base-metal compatibility
Existing coating or finish
Type and thickness of the deposit
Treatment concentration
Contact time and temperature
Rinsing procedure
Wastewater treatment requirements
Final surface appearance
Potassium Binoxalate Applications
Metal Surface Treatment
Potassium binoxalate may be used as an acidic component in selected metal-cleaning, polishing and surface-treatment formulations. It can assist with certain iron-containing stains, oxide residues and mineral deposits under controlled conditions.
It is not universally compatible with every alloy, coating or polished surface. Concentration, exposure time and rinsing conditions should be validated on representative test coupons before full-scale use.
Professional Cleaning Formulations
The product may be incorporated into formulated industrial or professional cleaning systems where controlled acidity and oxalate chemistry are required.
It should not be promoted as a general-purpose household cleaner. Formulators must assess user exposure, surface compatibility, labeling, packaging and local chemical regulations.
Analytical and Laboratory Reagents
Potassium hydrogen oxalate can be used in analytical chemistry, reagent preparation and research applications.
A standard industrial grade should not automatically be described as a primary standard. Applications requiring certified reference characteristics must use an appropriately qualified grade supported by the necessary certificate, traceability, uncertainty and test documentation.
Textile and Leather Processing
Potassium binoxalate has been used as a mordant or processing auxiliary in selected textile and leather operations. Its suitability depends on the fiber or substrate, dyes, process pH and discharge-control requirements.
Pilot testing is recommended to confirm shade, fastness, residue and substrate effects.
Specialty Photographic Processing
Potassium binoxalate has historical and specialty uses in certain photographic processes. Users should verify compatibility with the exact process chemistry rather than substituting it for another oxalate salt.
Chemical Processing
The product may function as an acidic oxalate source, processing aid or intermediate in suitably designed chemical systems. Reaction stoichiometry must account for its exact chemical form, purity and moisture content.
Potassium Binoxalate Solubility and Solution Preparation
Potassium binoxalate is more soluble in hot water than in cold water. Reference information reports a solubility of approximately 48.1 g per 100 g of water at 100°C, while cold-water dissolution is more limited.
When preparing a process solution:
Confirm the required concentration and hydration-state basis.
Use compatible process equipment and suitable-quality water.
Add the material gradually with controlled agitation.
Avoid generating airborne dust.
Control the temperature within the validated process range.
Check that the solution is clear before use.
Do not mix it with an unknown formulation or incompatible material.
Follow the current supplier SDS and site operating procedure.
These steps are general industrial considerations, not a substitute for a validated formulation or workplace risk assessment.
Factors That Can Affect Process Performance
Potassium binoxalate performance can change when any of the following variables change:
Product assay or hydration state
Solution concentration
Water hardness
pH
Temperature
Contact time
Agitation
Surface condition
Metal alloy
Soil or oxide composition
Rinsing efficiency
Presence of other complexing agents
Accumulation of dissolved metal ions
For repeatable production results, users should establish measurable bath-control and replacement criteria.
Which Potassium Binoxalate Grade Should You Choose?
Grade
Suitable uses
Important controls
Industrial grade
Formulated cleaning, metal treatment and general chemical processing
Assay, insoluble matter, iron, particle size and consistency
Reagent grade
Laboratory preparation, research and analytical work
Assay, chloride, sulfate, iron, trace impurities and test methods
Certified reference grade
Validated calibration or reference applications
Certification, traceability, uncertainty and defined test method
Custom specification
Processes with special impurity, particle-size or packaging requirements
Contracted limits and batch-specific COA
The lowest-priced grade is not always the lowest-cost option. Poor dissolution, excess insoluble matter or variable impurities can increase filtration, rework and process-control costs.
How Should Buyers Evaluate a Potassium Binoxalate Supplier?
A reliable supplier should be able to confirm product identity, not merely provide a commercial name.
Before approving a supplier, evaluate:
CAS number, formula and molecular weight
Anhydrous or hydrated form
Assay basis and analytical method
Batch-to-batch consistency
Relevant impurity limits
Availability of TDS, SDS and COA
Packaging and pallet configuration
Storage and shelf-life recommendations
Regulatory and transport information
Sample and pre-shipment testing options
Export-document capability
Change-notification and complaint procedures
Specifications copied from a generic database should not replace batch-specific quality documents.
What Documents Should a Supplier Provide?
Depending on the destination and intended use, buyers may request:
Certificate of Analysis
Safety Data Sheet
Technical Data Sheet
Product specification
Commercial invoice
Packing list
Certificate of Origin
Transport documentation
Regulatory declarations
Allergen, GMO or animal-origin statements when genuinely relevant
Inspection or third-party test report when contractually required
The document version, product name, CAS number and batch number should be consistent across the complete shipment file.
Packaging Options
Potassium binoxalate may be supplied in laboratory packs or industrial bags, depending on grade and order volume. A common industrial configuration is a lined 25 kg bag, but availability must be confirmed when requesting a quotation.
Packaging should protect the material from:
Moisture
Contamination
Physical damage
Label loss
Uncontrolled dust release
Custom packaging, palletization or labeling should be agreed before order confirmation.
Storage and Handling
Store potassium binoxalate in its original, tightly closed container in a cool, dry and well-ventilated location.
Recommended controls include:
Preventing moisture ingress
Avoiding incompatible chemicals
Keeping containers clearly labeled
Using suitable gloves and eye protection
Controlling dust during transfer
Washing after handling
Restricting access to trained personnel
Following the current SDS and local workplace rules
Do not store or handle the product near food, beverages or animal feed.
Potassium Binoxalate Safety Information
Potassium binoxalate is an oxalate chemical and should not be treated as a harmless salt. Supplier classifications may identify it as harmful if swallowed and harmful in contact with skin.
Avoid ingestion, inhalation of dust and contact with skin or eyes. Oxalates can interact with calcium in the body and may cause serious systemic effects following significant exposure.
Emergency procedures, first-aid measures and personal protective equipment must be based on the current SDS, actual workplace exposure and local regulations.
Transport and Regulatory Considerations
Transport classification can vary with product form, concentration, supplier classification and destination-country rules. Buyers should not rely on an online UN number copied from an unrelated product listing.
Before shipment, confirm:
Proper shipping name
UN number, if applicable
Hazard class and packing group
Marine or air transport restrictions
Destination-country inventory status
Required labels and documentation
Local storage and use restrictions
The shipment-specific SDS and dangerous-goods assessment should determine the final transport arrangement.
Why Source Potassium Binoxalate from AOZUN?
AOZUN supports international B2B buyers seeking potassium binoxalate for industrial, laboratory and specialty chemical applications.
Support may include:
Specification review before quotation
Confirmation of chemical identity and hydration state
Batch-specific quality documentation
Industrial and laboratory packaging discussions
Sample evaluation
Export-document coordination
Shipment planning
Technical communication during supplier qualification
Product availability, specification, regulatory status and packaging should be confirmed in the final quotation and sales contract.
Information to Include in Your RFQ
For a faster and more accurate quotation, provide:
Product name
CAS number
Required grade
Anhydrous or hydrated form
Minimum assay
Required impurity limits
Particle-size requirement
Intended application
Requested quantity
Packaging requirement
Destination port or delivery address
Required documentation
Sample requirement
Target delivery schedule
If your specification is based on an existing product, include its TDS or COA for technical comparison.
Frequently Asked Questions
What is potassium binoxalate?
Potassium binoxalate is another name for potassium hydrogen oxalate, the acidic monopotassium salt of oxalic acid. Its anhydrous formula is KHC₂O₄.
What is the CAS number of potassium binoxalate?
The CAS number for potassium hydrogen oxalate is 127-95-7.
What is the molecular weight of potassium binoxalate?
The molecular weight of anhydrous KHC₂O₄ is 128.13 g/mol. A hydrated form has a different molecular weight and must be identified separately.
Is potassium binoxalate the same as potassium tetroxalate?
No. Potassium binoxalate and potassium tetroxalate have different formulas, molecular weights, acidities and typical applications. They should not be substituted without technical approval.
Is potassium binoxalate soluble in water?
It has limited solubility in cold water and is more soluble in hot water. Actual dissolution depends on temperature, agitation, particle size and water composition.
What is potassium binoxalate used for?
Typical uses include selected metal surface-treatment formulations, analytical reagents, textile or leather processing, professional cleaning systems, specialty photography and chemical processing.
Can potassium binoxalate remove rust?
It may assist in removing certain iron-containing stains or oxide deposits in properly designed formulations. Surface compatibility, concentration and treatment time must be tested before production use.
Is potassium binoxalate a primary standard?
Not every potassium binoxalate product is a primary standard. Only a specifically qualified or certified grade supported by appropriate documentation should be used for validated reference applications.
Is potassium binoxalate food grade?
A generic industrial or reagent-grade product must not be assumed to be food grade. Food use would require an explicitly qualified grade and compliance with all applicable regulations.
What specifications should buyers compare?
Compare assay, hydration state, water-insoluble matter, chloride, sulfate, iron, heavy metals, moisture, particle size, solution clarity and batch documentation.
How should potassium binoxalate be stored?
Store it tightly closed in a dry, cool and ventilated place, protected from moisture, contamination and incompatible chemicals.
Can AOZUN provide a sample and COA?
Sample availability, batch documentation, specification and packaging can be discussed during the quotation process. Include your application and required limits in the RFQ.
Request a Potassium Binoxalate Quote
Contact AOZUN for potassium binoxalate pricing, specifications, packaging and export information.
For an accurate proposal, send us your required grade, assay, impurity limits, quantity, application, destination and delivery schedule. Our team will review the requirement and confirm the appropriate commercial specification before order placement.
Product Description
Potassium Binoxalate (Potassium Hydrogen Oxalate) – CAS 127-95-7
Product Name: Potassium Binoxalate Synonyms: Potassium Hydrogen Oxalate, Potassium Acid Oxalate CAS Number: 127-95-7 Molecular Formula: KHC₂O₄ Molecular Weight: 128.13 g/mol Appearance: White crystalline powder Solubility: Soluble in water
What Is Potassium Binoxalate?
Potassium Binoxalate (CAS 127-95-7) is an acidic potassium salt of oxalic acid. It is commonly used as a laboratory reagent and chemical intermediate. The product is valued for its stable crystalline structure and controlled acidity.
This compound is widely applied in analytical chemistry, metal surface treatment, and specialty formulations.
Key Features
High purity and consistent quality
Stable crystalline form
Good water solubility
Controlled acidic properties
Suitable for laboratory and industrial use
Applications of Potassium Binoxalate
1. Analytical Chemistry
Used as a primary standard or reagent in laboratory analysis. Provides reliable acidity control in titration procedures.
2. Chemical Intermediate
Applied in the production of specialty oxalate compounds. Used in research and formulation development.
3. Metal Surface Treatment
Utilized in metal cleaning and finishing processes. Helps remove rust and oxide layers.
4. Textile and Dye Industry
May be used in specific dyeing or bleaching systems. Improves treatment consistency.
Technical Specifications
Item
Specification
Purity
≥ 99%
Appearance
White crystalline powder
pH (aqueous solution)
Acidic
Moisture
≤ 0.5%
(Custom specifications available upon request.)
Packaging Options
25 kg fiber drums
25 kg kraft paper bags
Customized packaging available
Proper storage: Store in a cool, dry, well-ventilated area. Keep container tightly closed. Avoid moisture exposure.
Safety Information
Potassium Binoxalate is acidic and should be handled with care. Use protective gloves and eye protection. Avoid inhalation and direct skin contact.
Refer to the Safety Data Sheet (SDS) for detailed handling instructions.
Frequently Asked Questions (FAQs)
1. What is the difference between potassium binoxalate and potassium oxalate?
Potassium binoxalate is an acid salt containing one hydrogen atom. Potassium oxalate is a neutral salt with different chemical properties.
2. Is Potassium Binoxalate soluble in water?
Yes, it is soluble in water and forms an acidic solution.
3. What industries commonly use CAS 127-95-7?
It is used in laboratories, chemical manufacturing, metal treatment, and textile processing.
4. Can you provide customized purity levels?
Yes, we can supply customized specifications according to your application needs.
5. Do you provide export documentation?
Yes, we provide COA, SDS, MSDS, and other required export documents.
Why Choose Us?
As an experienced chemical export supplier, we focus on:
Stable production and supply chain
Strict quality control
Competitive pricing
Fast international shipping
Professional export documentation support
We support long-term and stable cooperation with global partners.
Contact Us
For quotation, technical data, or samples, please contact: