Sodium dihydrogen phosphate anhydrous (NaH2PO4) is a versatile compound used as a pH buffer and emulsifier in food products, a laboratory buffer, and a pH adjuster in water treatment. It finds applications in pharmaceuticals, electroplating, and chemical synthesis. Careful handling is required due to its potential skin, eyes, and respiratory system irritation. Stored in a cool, dry place, it serves various industries as a raw material and reagent to processes ranging from food manufacturing to scientific research and water treatment, which is crucial in maintaining pH levels in diverse applications. Let’s gain some in-depth knowledge about this excellent chemical.

The chemical formula for sodium dihydrogen phosphate anhydrous is NaH2PO4. Structurally, it consists of sodium cations (Na+) and dihydrogen phosphate anions (H2PO4^-). The compound has a monoclinic crystal structure. In its solid state, each sodium cation is surrounded by four oxygen atoms: two from two different phosphate groups and two from neighbouring water molecules. The dihydrogen phosphate anions form a network through hydrogen bonding and ionic interactions with the sodium cations. This arrangement contributes to its properties, such as solubility and pH buffering capabilities.

Depending on its hydration state, sodium dihydrogen phosphate (NaH2PO4) can exist in different forms.

Anhydrous Form: This form is without water molecules bound to the crystal lattice. It is denoted as NaH2PO4.

Monohydrate: In this form, one water molecule is bound to each formula unit of NaH2PO4. It is denoted as NaH2PO4·H2O.

Dihydrate: In the dihydrate form, two water molecules are bound to each formula unit of NaH2PO4. It is denoted as NaH2PO4·2H2O.

These hydrated forms may have different physical properties, such as solubility and crystalline structure, than the anhydrous form. The choice of which form to use depends on the specific application and desired properties.

The physical properties of sodium dihydrogen phosphate anhydrous (NaH2PO4) include:

Appearance: It typically appears as a white, crystalline powder or granules.

Odor: It is usually odorless.

Density: The density of sodium dihydrogen phosphate anhydrous is approximately 2.36 g/cm³.

Melting Point: It melts at around 190°C to 230°C (374°F to 446°F), depending on the purity of the compound.

Solubility: It is soluble in water, with solubility increasing with temperature. It is practically insoluble in organic solvents such as ethanol.

pH: A 1% solution of NaH2PO4 in water has a pH of around 4.5 to 5.5, making it slightly acidic.

Hygroscopicity: Anhydrous sodium dihydrogen phosphate has some hygroscopic properties and can absorb moisture from the atmosphere if exposed to air for prolonged periods, though not as much as its hydrated forms.

The chemical composition of sodium dihydrogen phosphate anhydrous (NaH2PO4) consists of sodium cations (Na+) and dihydrogen phosphate anions (H2PO4^-). Here are the fundamental properties of this compound:

pH Buffer: Sodium dihydrogen phosphate anhydrous acts as a buffer in aqueous solutions. It can resist changes in pH when small amounts of acid or base are added.

Water Solubility: It is highly soluble in water, which makes it useful in various aqueous applications such as buffering solutions, food processing, and pharmaceutical formulations.

Acidic Properties: In aqueous solutions, sodium dihydrogen phosphate anhydrous exhibits slightly acidic properties, with a pH typically around 4.5 to 5.5 for a 1% solution.

Crystal Structure: It has a monoclinic crystal structure in its solid form.

Hygroscopicity: While anhydrous, it still possesses some degree of hygroscopicity, meaning it can absorb moisture from the air.

Chemical Reactivity: Sodium dihydrogen phosphate anhydrous can participate in various chemical reactions, including acid-base reactions, phosphorylation reactions, and reactions involving the displacement of the hydrogen ion (H+) by other cations.

Sodium dihydrogen phosphate anhydrous (NaH2PO4) finds many applications across various industries.

Buffering Agent: In food processing, maintaining the pH of products is crucial for flavour, texture, and shelf-life. Sodium dihydrogen phosphate anhydrous acts as a buffer to stabilise the pH, preventing excessive acidity or alkalinity. For example, it helps control the acidity of processed cheeses, canned foods, and beverages.

Emulsifier: As an emulsifying agent, it helps stabilise oil-in-water emulsions, preventing separation and improving the texture and mouthfeel of products like processed cheeses and salad dressings.

Leavening Agent: In baking powders, it reacts with bicarbonate to produce carbon dioxide gas, which leavens dough and batter, resulting in lighter and fluffier baked goods like cakes, muffins, and pancakes.

Water Treatment:

pH Adjustment: In water treatment, maintaining the pH within the desired range is essential for effective disinfection, corrosion control, and clarity. Sodium dihydrogen phosphate anhydrous is used to adjust water pH in swimming pools, aquariums, and industrial processes, ensuring optimal conditions for water treatment chemicals and equipment.

Corrosion Inhibition: By stabilising the pH, it helps mitigate corrosion in metal pipes, tanks, and equipment, prolonging their lifespan and reducing maintenance costs.

Laboratory Applications:

Buffer Solution: In laboratories, buffer solutions containing sodium dihydrogen phosphate anhydrous are widely used in biochemistry, molecular biology, and analytical chemistry. These buffers help maintain a constant pH during experiments, ensuring accurate and reproducible results. They are good in enzyme assays, DNA/RNA isolation, and cell culture techniques.

Analytical Chemistry: It is used as a standard reference material in analytical chemistry for calibrating pH meters and conducting titrations.

Pharmaceuticals:

Buffering Agent: In pharmaceutical formulations, maintaining the pH of drug solutions is critical for stability, solubility, and bioavailability. Sodium dihydrogen phosphate anhydrous is added to oral solutions, injections, and topical preparations to adjust and maintain the pH within the desired range, ensuring the efficacy and safety of the drug product.

Excipient: As an excipient in tablet formulations, it aids in the disintegration and dissolution of tablets, facilitating the release of the active pharmaceutical ingredient in the gastrointestinal tract for absorption.

Chemical Synthesis: It is a reactant, catalyst, or pH regulator in various chemical synthesis processes. For example, it is used in speciality chemicals, detergents, and industrial cleaners.

Electroplating: In electroplating baths, it helps stabilise the pH, ensuring uniform deposition of metals onto substrates and improving the quality and appearance of plated products.

Personal Protective Equipment (PPE): It is crucial to wear appropriate PPE when handling sodium dihydrogen phosphate anhydrous. Safety goggles or a face shield should be worn to protect the eyes from potential splashes or dust. For protection against skin contact and absorption, it is necessary to wear gloves made of chemical-resistant materials and a lab coat or protective clothing.

Handling and Storage: Sodium dihydrogen phosphate anhydrous should be handled in a well-ventilated area to prevent inhalation of dust or fumes. Store it in tightly sealed containers away from incompatible materials and moisture. Keeping containers closed when not in use helps prevent contamination and moisture absorption, maintaining the integrity of the compound.

Avoiding Contact: Minimize skin and eye contact with sodium dihydrogen phosphate anhydrous to prevent irritation or injury. In case of contact, it is essential to immediately rinse the affected area with plenty of water and seek medical attention if irritation persists. Ingestion or inhalation of the compound should be avoided, and medical attention should be sought promptly if exposure occurs.

Spill and Leak Procedures: Proper spill and leak procedures should be followed to contain sodium dihydrogen phosphate anhydrous and prevent environmental contamination. Spills should be contained, and absorbent materials should be used to soak up the spills. Cleanup should be performed wearing appropriate PPE to avoid exposure, and the material should be disposed of properly according to local regulations.

Fire and Explosion Hazards: Although sodium dihydrogen phosphate anhydrous is not flammable or combustible, precautions should be taken to avoid exposure to heat sources or flames, as it may release irritating or toxic fumes when heated to decomposition. Keep it away from strong oxidising agents and combustible materials to minimise fire or explosion hazards.

Emergency Procedures: Awareness of emergency procedures and the location of safety equipment is essential when working with sodium dihydrogen phosphate anhydrous. Eyewash stations, emergency showers, and fire extinguishers should be readily accessible, and individuals should know how to respond in case of fire, spill, or exposure emergency.

Safe Disposal: Proper disposal of sodium dihydrogen phosphate anhydrous is crucial to prevent environmental contamination. Disposal should be carried out according to local regulations and guidelines, and contact with the local waste disposal authority may be necessary to ensure compliance with proper disposal procedures.

Ensuring safety measures are paramount when handling sodium dihydrogen phosphate anhydrous. From wearing appropriate personal protective equipment to following spill and emergency procedures, every precaution is essential to minimize risks and ensure safe usage. For reliable sourcing of high-quality sodium dihydrogen phosphate anhydrous in India, look no further than Annexe Chem. As a reputable manufacturer and supplier, Annexe Chem prioritises safety and provides comprehensive safety guidelines to support our customers. With our commitment to quality and safety, you can trust Annexe Chem for all your sodium dihydrogen phosphate anhydrous needs.

Contact Annexe Chem today for reliable products and dependable safety support.