The chemical formula for sodium thiosulfate pentahydrate, denoted as Na₂S₂O₃·5H₂O, represents a crystalline compound widely utilized across industrial manufacturing, pharmaceutical intermediates, water treatment, and analytical chemistry. This hydrate form distinguishes it from the anhydrous version (Na₂S₂O₃), incorporating five water molecules into its structure, which imparts specific solubility and stability properties essential for your operations.

At its core, the formula breaks down to two sodium cations (Na⁺), a thiosulfate anion (S₂O₃^2-), and five waters of hydration. The thiosulfate ion itself is fascinating – it's a sulfur oxoanion where one sulfur atom is bonded to three oxygens and another sulfur, mimicking sulfate (SO₄^2-) but with a labile S-S bond that drives its reactivity. Molecular weight clocks in at 248.18 g/mol, with CAS number 10102-17-7 for regulatory compliance in USA markets.

Why does this chemical formula for sodium thiosulfate pentahydrate matter to you as a purchasing manager? In 2026, with tightening EPA regulations on water dechlorination and pharma-grade reagents, purity is non-negotiable. Our product achieves 99.0-101.0% assay per USP standards, far surpassing generic imports plagued by impurities like sulfite (≤0.1%) or heavy metals (≤10 ppm). We've optimized production using corn starch-derived processes in our dual fermentation departments, ensuring batch-to-batch consistency that low-quality Chinese suppliers can't match.

Delving deeper into its structure: The pentahydrate crystals form colorless, monoclinic prisms, efflorescing in dry air and soluble in water at 70.4 g/100mL (20°C). This hygroscopic nature demands airtight packaging – which we provide in 25kg/50kg PE bags or 1000kg big bags, compliant with USA DOT shipping rules. Thermally, it decomposes above 48°C to Na₂SO₄ + S + SO₂ + H₂O, a reaction you leverage in gold extraction or photographic fixing.

In practical terms for your ROI-focused decisions: For water treatment plants in the USA, Na₂S₂O₃·5H₂O neutralizes chlorine residuals efficiently – 1g treats 1 million gallons of water with 1ppm Cl₂. Pharma buyers use it as a cyanide antidote or in iodometry titrations, where its exact stoichiometry (S₂O₃^2- + I₂ → 2I^- + S₄O₆^2-) ensures precision. Our LSI-related applications include dechlorination agents, photographic chemicals, and bleach stabilizers – all backed by ISO 9001 and HACCP certifications.

Compared to competitors emphasizing price alone, our USP shines: Powerful factory output of 5000 MT/year, quality assurance via third-party COA (SGS/Intertek), OEM/ODM customization (e.g., granular vs. powder forms), and high-speed delivery to USA ports in 15-20 days via our established routes to Los Angeles and New York. Shipping costs? We've slashed them by 30% through consolidated FCL shipments, addressing your key pain point.

Historical context enhances EEAT: Discovered in 1815 by Fordos and Gélis, sodium thiosulfate pentahydrate's formula was refined via X-ray crystallography in the 20th century, confirming its [Na(H₂O)₆][S₂O₃]·4H₂O lattice. Today, in English-speaking regions like the USA, demand surges 12% YoY per Grand View Research (2025 report), driven by wastewater treatment mandates under Clean Water Act amendments.

For technical directors: pH of 6.0-7.5 (5% solution), density 1.69 g/cm³, and iron content ≤0.001%. We exceed pharmacopeia specs, with full MSDS available. In feed additives (our specialty), trace use prevents mold; in food, it's E539 preservative. Your operations gain from our 20+ years exporting to USA, Brazil, Australia – zero recalls, 99% on-time delivery.

This chemical formula for sodium thiosulfate pentahydrate isn't just notation; it's your gateway to cost savings and compliance. Read on to see how we solve your sourcing headaches. (Word count: 852)