Potassium Chromate Extra Pure
Potassium Chromate Extra Pure is a high-purity, bright yellow crystalline compound known for its reliability in precise laboratory analyses. It is commonly used as an indicator in argentometric titrations, particularly for the detection of chloride ions in solution. Its strong oxidizing nature also makes it valuable in various industrial processes, including metal passivation, pigment manufacturing, and dyeing applications. In educational and research laboratories, it serves as a dependable reagent for redox reactions and chemical demonstrations. Given its toxicity and environmental hazards, it should be stored securely and handled using proper protective equipment to ensure safety and compliance with regulatory standards.
Potassium Chromate Extra Pure
PRIMARY USES
- Analytical Chemistry:
- Used as a reagent in titration, especially for detecting chloride ions using the Mohr method.
- Acts as an oxidizing agent and indicator in redox and precipitation reactions.
- Laboratory Reagent:
- Used for preparing chromate-based solutions and standard reference materials.
- A common source of chromate ions (CrO₄²⁻) for synthesis and research.
- Pigment Manufacturing:
- Serves as a precursor in producing yellow pigments and anti-corrosion coatings.
SECONDARY USES
- Textile & Dye Industry:
- Involved in dye mordanting processes to help fix dyes to fibers.
- Glass & Ceramic Manufacturing:
- Contributes to the coloration of glass and glazes in decorative ceramics.
- Corrosion Inhibition:
- Used in chromate conversion coatings for metal surface treatment (especially aluminum).
1. Basic Identification Attributes
- Chemical Name: Potassium Chromate
- CAS Number: 7789-00-6
- HS Code: 2841.50.00
- Molecular Formula: K₂CrO₄
- Synonyms:
- Dipotassium chromate
- Chromic acid, dipotassium salt
- Yellow potassium chromate
2. Physical & Chemical Properties
- Physical State: Solid (crystalline powder)
- Color & Odor: Bright yellow, odorless
- Boiling Point & Melting Point:
- Melting Point: ~975 °C (decomposes)
- Boiling Point: Not applicable (decomposes before boiling)
- Density/Specific Gravity: ~2.73 g/cm³
- Solubility:
- Soluble in water (~62 g/L at 20 °C)
- Insoluble in alcohol
- pH Level: Alkaline (~8.6 in aqueous solution)
- Vapor Pressure & Volatility: Negligible vapor pressure
- Flash Point: Not flammable
- Autoignition Temperature: Not applicable
- Viscosity: Not applicable
3. Safety & Hazard Attributes
- Hazard Class (GHS Classification):
- Oxidizing, Carcinogenic, Toxic, Environmentally Hazardous
- NFPA Ratings:
- Health: 3
- Flammability: 0
- Reactivity: 1
- Exposure Limits:
- OSHA PEL (as Cr(VI)): 0.005 mg/m³ (TWA)
- ACGIH TLV: 0.05 mg/m³ (as Cr)
- Reactivity:
- Incompatible with reducing agents, organic materials, strong acids
- Reacts with acids to produce toxic chromium compounds
4. Storage & Handling Attributes
- Storage Conditions:
- Store in a cool, dry, well-ventilated area away from light and reducing agents
- Incompatible Materials:
- Organic substances, acids, reducing agents, combustible materials
- Container Type:
- Corrosion-resistant sealed containers (e.g., glass or HDPE)
- Shelf Life & Expiration Date:
- Stable under recommended conditions; check regulatory expiration guidance
- Special Handling Requirements:
- Use in fume hood
- Wear chemical-resistant gloves, goggles, lab coat, and appropriate respiratory protection
5. Regulatory & Compliance Attributes
- Regulatory Status:
- REACH Registered, OSHA regulated (Cr VI compound)
- Listed by IARC as Group 1 Carcinogen
- Subject to SARA Title III, TSCA, RCRA
- Transportation Restrictions:
- UN Number: UN 3288
- Hazard Class: 6.1 (Toxic substances)
- Waste Disposal Method:
- Dispose as hazardous waste per EPA and RCRA guidelines
- Use licensed chemical waste disposal contractor
6. Environmental & Health Impact
- Ecotoxicity:
- Highly toxic to aquatic life (LC50 < 1 mg/L for fish and invertebrates)
- Persistence in Environment:
- Persistent and non-biodegradable; Cr(VI) form is environmentally mobile
- Carcinogenicity/Mutagenicity:
- Known human carcinogen (IARC Group 1)
- Mutagenic and teratogenic risks with chronic exposure
- Biodegradability:
- Not biodegradable; requires chemical reduction to Cr(III) for detoxification
SAFETY PRECAUTIONS
Personal Protective Equipment (PPE):
- Wear chemical-resistant gloves (nitrile or butyl rubber).
- Use tightly fitting safety goggles or a face shield.
- Lab coat with full coverage is essential.
- Use a dust mask or respirator if ventilation is insufficient.
- Handle in a fume hood due to toxic and carcinogenic properties.
Handling:
- Avoid all contact with skin, eyes, and clothing.
- Do not breathe dust.
- Do not ingest.
- Handle with extreme care due to its oxidizing and carcinogenic nature.
- Use only in well-ventilated areas.
Storage:
- Store in a tightly closed, corrosion-resistant container.
- Keep in a cool, dry, and well-ventilated location.
- Store away from combustible materials and reducing agents.
FIRST AID MEASURES
Inhalation:
- Move the exposed person to fresh air immediately.
- Seek urgent medical attention.
- If not breathing, give artificial respiration.
Skin Contact:
- Immediately wash skin with soap and water for at least 15 minutes.
- Remove contaminated clothing.
- Seek immediate medical assistance.
Eye Contact:
- Rinse cautiously with water for 15–20 minutes.
- Lift eyelids occasionally.
- Get medical help without delay.
Ingestion:
- Do not induce vomiting.
- Rinse mouth with water.
- Seek emergency medical care immediately.
FIRE FIGHTING MEASURES
Flammability:
- Not flammable, but a powerful oxidizer—enhances the burning of other materials.
Extinguishing Media:
- Use water spray, foam, dry chemical, or CO₂ depending on the surrounding fire.
Hazardous Combustion Products:
- Emits toxic fumes including chromium oxides and potassium oxides when heated.
Firefighter Protection:
- Full protective gear and self-contained breathing apparatus (SCBA) required.
- Keep containers cool with water spray.
- Avoid breathing vapors or dust during fire.