When sourcing chemicals for large-scale industrial processes, procurement managers and engineers must consider every specification that impacts performance and cost. One frequently overlooked yet fundamental property is sodium sulfite molecular weight. At 126.04 g/mol for the anhydrous form (Na2SO3), this figure directly influences dosing calculations, purity verification, and even shipping logistics. Whether you manage a power plantâs boiler water chemistry, run a pulp mill, or oversee textile bleaching operations, a precise understanding of molecular weight can mean the difference between optimal efficiency and costly mistakes.
This comprehensive guide explores sodium sulfite molecular weight from multiple anglesâchemical composition, its role in oxygen scavenging stoichiometry, comparisons with related salts like sodium sulfate and sodium metabisulfite, and practical procurement insights. Weâll also answer frequent buyer questions such as âwhat is sodium sulfate potasâ (a common search confusion), âsodium sulphate vs sodium sulfiteâ, and âwhere to buy sodium sulfiteâ with confidence in product quality.
The molecular weight of anhydrous sodium sulfite is derived from its atomic constituents: two sodium atoms (22.99 g/mol each), one sulfur atom (32.06 g/mol), and three oxygen atoms (16.00 g/mol each). The calculation yields:
(2 Ă 22.99) + 32.06 + (3 Ă 16.00) = 45.98 + 32.06 + 48.00 = 126.04 g/mol.
For the heptahydrate form (Na2SO3·7H2O), the water of crystallization adds 7 Ă 18.015 g/mol, bringing the total to approximately 252.15 g/mol. This distinction is crucial when purchasing sodium sulfite, as hydrated forms require roughly double the mass to deliver the same active Na2SO3 content. Reputable suppliers will clearly state whether their product is anhydrous (typically 96â98% purity) or heptahydrate, a factor that directly impacts your unit cost and storage requirements.
Many buyers overlook the difference, leading to under-dosing in critical applications like boiler water oxygen removal. Always verify the molecular weight and assay on the Certificate of Analysis (CoA) when ordering bulk quantities. As a top-tier Chinese exporter, Hailei Chemicalâs sodium sulfite is anhydrous, consistently assayed at â„96%, providing predictable stoichiometric performance.
One of the largest industrial uses of sodium sulfite is as an oxygen scavenger in boiler feedwater. Dissolved oxygen causes pitting corrosion in steel boiler tubes, dramatically reducing equipment lifespan. The deoxygenation reaction is straightforward:
2 Na2SO3 + O2 â 2 Na2SO4
Using the sodium sulfite molecular weight, we can calculate the exact chemical requirement: to remove 1 ppm of dissolved oxygen from 1,000 liters of water, you need approximately 7.88 ppm of anhydrous sodium sulfite. This is derived from the stoichiometric ratio: 2 moles of Na2SO3 (252.08 g) react with 1 mole of O2 (32.00 g), giving a mass ratio of 252.08:32, or 7.8775:1.
For high-pressure boilers, precise dosing is non-negotiable. Under-treatment leaves oxygen unchecked, while over-treatment wastes chemical and increases dissolved solids (converting to sodium sulfate, which may exceed blowdown limits). Both errors can be avoided by centering your calculations on sodium sulfite molecular weight. Procurement teams who understand this relationship can better evaluate supplier quotesâseemingly cheaper hydrated material may actually be far more expensive per kilogram of available Na2SO3.
When buying in tonnage, miscalculating due to a wrong molecular weight assumption can waste thousands of dollars annually. Always confirm the specification sheet and perform a quick validation using the 7.88 rule. Hailei Chemical supplies premium anhydrous sodium sulfite with guaranteed purity, making dose calculations simple and reliable.
A surprisingly common search query among procurement professionals is âwhat is sodium sulfate potasâ. This often stems from confusion between sodium sulfite (Na2SO3), sodium sulfate (Na2SO4), and potassium salts used in similar industries. While there is no single chemical called âsodium sulfate potas,â the phrase may reflect a user trying to understand the difference between sodium sulfate, potassium sulfate, or perhaps even sodium potassium sulfate double salts.
Letâs clarify the molecular weights and roles:
The takeaway for industrial buyers: substituting one for the other can be disastrous. If your boiler treatment program expects sodium sulfiteâs reducing power, using sodium sulfate (the oxidized form) will provide zero oxygen removal. Similarly, potassium sulfite could work chemically but would add potassium ions that may interfere with water chemistry. Always check the molecular formula and molecular weight on the SDS to ensure you are receiving exactly what your process requires.
The difference between âsodium sulphateâ (alternative spelling) and sodium sulfite goes far beyond one oxygen atom. Their distinct molecular weightsâ142.04 vs. 126.04âare the first clue that these are not interchangeable. Sodium sulphate is largely inert, often used in kraft pulp processes and as a drying agent, while sodium sulfite actively participates in reduction reactions.
For buyers, confusing the two can lead to order errors. Weâve seen purchase orders specify âsodium sulfiteâ but with an expected purity corresponding to sulfate characteristicsâa red flag that the buyer may be unfamiliar with the exact chemical. Hereâs a quick verification approach: ask your supplier for the molecular weight and heat of solution. Sodium sulfite dissolves endothermically (the solution cools), whereas sodium sulfate can show an exothermic dissolution depending on hydration. Such simple checks can prevent costly mis-shipments.
When evaluating suppliers, insist on clear labeling and CoAs that state the molecular weight and chemical formula. Our sodium sulfite is consistently supplied as anhydrous Na2SO3 with a molecular weight of 126.04, backed by ISO-certified testingânever mislabeled sulfate.
Another frequent comparison is sodium metabisulfite vs sodium sulfite. Sodium metabisulfite (Na2S2O5) has a molecular weight of 190.11 g/mol. In water, it hydrolyzes to form sodium bisulfite (NaHSO3) and ultimately can act as a source of SO2. While both are used as oxygen scavengers and reducing agents, their equivalence is not one-to-one.
On a molar basis, two moles of sodium metabisulfite (380.22 g) provide the equivalent reducing capacity of two moles of sodium sulfite (252.08 g) because each Na2S2O5 yields one effective SO32â ion. However, the reaction pathways differ, and metabisulfite often releases sulfur dioxide gas, which can cause odor and handling issues. In closed boiler systems, sodium sulfite is preferred for its clean, gas-free reaction that simply converts to harmless sulfate.
For procurement, the choice boils down to process compatibility and cost per unit of reducing power. By expressing both on an equivalent sodium sulfite molecular weight basis, you can compare apples to apples. Typically, anhydrous sodium sulfite offers better value and simpler handling for large-scale water treatment. Many power plants have standardized on it precisely because the stoichiometry using the 126.04 molecular weight is so predictable.
When searching âwhere to buy sodium sulfite,â youâll encounter countless suppliers, from local distributors to direct manufacturers. However, not all sodium sulfite is created equal. A key indicator of quality is whether the offered purity aligns with the theoretical molecular weight. If a supplier advertises 96â98% anhydrous Na2SO3, you can cross-check: the molecular weight of the pure material is 126.04, and any impurities will lower the effective active content. Ask for an iodometric titration result or CoA that confirms the actual assay.
Here are practical benchmarks for evaluating a sodium sulfite supplier:
As a leading Chinese manufacturer and exporter, Hailei Chemical provides exactly this level of transparency and reliability. Our anhydrous sodium sulfite, produced under rigorous quality control, meets technical grade and food grade standards. When you request a quote, we supply full molecular weight and purity data so you can calculate your exact requirements.
Sodium sulfite molecular weight also plays a subtle but important role in logistics. Because the material is shipped in solid form, the weight per unit that counts toward freight costs is the actual mass loaded. However, what you truly pay for is the available chemical functionality â the number of moles of Na2SO3 delivered. A buyer sourcing heptahydrate will ship roughly twice the weight (due to water of crystallization) to achieve the same active moles, incurring higher freight charges. Switching to anhydrous sodium sulfite, with its lower molecular weight per active unit, can slice ocean freight and warehousing costs significantly.
For a typical 20-foot container hauling 20 metric tons, anhydrous sodium sulfite at 98% purity delivers approximately 19.6 tons of pure Na2SO3. The heptahydrate equivalent would require nearly 39 tons to achieve the same number of active moles, doubling your logistics spend. When extending this calculation across annual procurement volumes, the savings are substantial. This is one more reason why savvy buyers specify anhydrous material and verify the supplierâs declared molecular weight and assay.
Furthermore, understanding molecular weight helps calculate dangerous goods classification impact. Sodium sulfite is not typically regulated as hazardous for transport, but high-purity anhydrous material may require careful declaration. Always partner with a supplier who provides accurate shipping documents referencing the correct chemical identity and molecular weight.
To bridge the gap between theory and daily operations, here is a step-by-step guide to calculating sodium sulfite dosing using its molecular weight:
1. Determine oxygen content in feedwater: Measure dissolved oxygen in mg/L (ppm) using a calibrated meter. Example: 5 ppm O2.
2. Calculate stoichiometric sodium sulfite requirement: Use the ratio 7.88 mg Na2SO3 per 1 mg O2. So for 5 ppm O2 in 1,000 liters, you need 5 Ă 7.88 = 39.4 mg/L of pure Na2SO3.
3. Adjust for purity: If your sodium sulfite is 97% pure, divide by 0.97. Requirement = 40.6 ppm of technical product.
4. Convert to mass flow: For a boiler feedwater flow of 100 mÂł/h, the dosing pump should deliver 100,000 L/h Ă 40.6 mg/L = 4,060 g/h = 4.06 kg/h of sodium sulfite.
5. Prepare solution concentration: Many plants use a 10% (w/w) solution. The daily batch can be prepared by dissolving the required solid in deaerated water, using a mixer that prevents oxidation.
These steps, rooted in the molecular weight of 126.04 g/mol, ensure optimal chemical usage. Frequent errors like assuming a 1:1 weight ratio of sulfite to oxygen can cause severe under-treatment. Train your operations team on these fundamentals, and always cross-check against the supplierâs CoA.
For pulp and paper mills that use sodium sulfite in pulping liquor or as a bleach neutralizer after chlorine dioxide stages, similar stoichiometric precision applies. The reaction of sodium sulfite with residual oxidizing agents can be calibrated to avoid fiber damage and excessive chemical costs, all referencing the same molecular weight.
Industrial grades of sodium sulfite are defined by more than just purity. The molecular weight of 126.04 is the anchor against which impurity limits are set. Typical specifications for technical-grade anhydrous sodium sulfite include:
These values assume the primary component has the expected molecular weight. Any deviation, such as excessive sulfate or carbonate, effectively reduces the available sulfite per kg, forcing you to overfeed to meet oxygen removal targets. High-quality suppliers tightly control these parameters. When you request a sample, ask for a full assay and compare the calculated molecular weight contribution of impurities against the stated purity. This level of due diligence separates transactional buyers from true procurement experts.
The molecular weight of sodium sulfite also hints at its sensitivity to oxidation. Over time, exposure to air and moisture causes Na2SO3 (126.04 g/mol) to gain an oxygen atom, forming Na2SO4 (142.04 g/mol). This gradual conversion reduces active content, and because the molecular weight increases, a simple weight check of stored inventory may mislead operators into thinking they have adequate material when in reality the reducing capacity has plummeted.
Best practices include:
These measures protect the molecular weight-based dosing calculations youâve established for your process, ensuring consistent performance from shipment to consumption.
At Weifang Hailei Fine Chemical Co., Ltd., we treat sodium sulfite molecular weight not as a mere number on a spec sheet, but as the cornerstone of value delivery. Our anhydrous sodium sulfite is manufactured to a minimum purity of 96%, with an actual assay often exceeding 97%, giving you more active moles per kilogram purchased. We supply to power plants, paper mills, textile finishing plants, and leather tanneries worldwide, with full traceability and compliance documentation.
Our team can assist with:
Backed by decades of fine chemical expertise, Hailei Chemical is the partner you can trust for consistent, high-quality sodium sulfite that aligns perfectly with your operational calculations.
Mastering sodium sulfite molecular weight unlocks significant advantages in boiler water treatment, chemical procurement, and logistics optimization. By basing your decisions on the 126.04 g/mol standard for anhydrous Na2SO3, you can precisely dose oxygen scavengers, evaluate supplier integrity, and reduce total delivered cost. Avoid the common pitfalls of confusing sodium sulfite with sulfate or metabisulfite by verifying molecular weight and purity on every order.
Whether you are expanding your supplier base or facing new boiler efficiency targets, a robust understanding of this fundamental property puts you in control. Explore our sodium sulfite product page for detailed specifications and packaging options. When youâre ready to discuss your requirements or need a competitive quotation, visit our Get a Quote page to connect directly with our technical sales team. Letâs calculate the exact volume you needâmolecular weight included.
When sourcing potassium sulphateâalso known as sulfate of potash (SOP)âfor highâvalue agriculture or precision industrial processes, one of the first technical parameters procurement specialists examine is potassium sulphate molecular weight. With a precisely defined value of 174.26 g/mol for the anhydrous K2SO4 molecule, this figure is far more than a chemistry textbook entry. It directly influences purity verification, stoichiometric calculations for batch formulations, and the predictable solubility behaviour that underpins everything from chlorideâfree drip irrigation to pharmaceutical excipient quality. In this comprehensive guide, we explain why molecular weight matters, how it connects to the potassium sulfate chemical formula K2SO4, and what every B2B buyer should know about potassium sulfate solubility in water, realâworld performance, and reliable sourcingâdrawing on decades of expertise from Weifang Hailei Fine Chemical Co., Ltd.
The potassium sulfate chemical formula K2SO4 tells a concrete story about composition. Each formula unit consists of two potassium cations (K+) and one sulfate anion (SO42â). For procurement professionals, this simple notation unlocks a wealth of qualityâcontrol data. Based on the standard atomic weights (K = 39.10, S = 32.07, O = 16.00), the theoretical molecular weight is 2(39.10) + 32.07 + 4(16.00) = 174.26 g/mol. Any deviation in an assay result from this figure suggests the presence of impuritiesâtypically residual chlorides, sodium, or moisture. Because Hailei Chemicalâs SOP is manufactured via the Mannheim process using pharmaceuticalâgrade potassium chloride and sulfuric acid, our typical potassium sulphate molecular weightâverified assay consistently delivers K2O content of 50% minimum by weight, with chloride levels below 0.5%. That purity makes it the premier choice for chlorineâsensitive crops like tobacco, citrus, and avocados, as well as for the most demanding industrial applications.
Industrial users rely on the molecular weight to convert between mass and molar quantities. For example, a glass batch recipe requiring 0.5 mol of K2SO4 as a refining agent translates to exactly 87.13 grams of pure product. If the supplied material contains inert solids or free moisture, a simple stoichiometric calculation based on 174.26 g/mol becomes unreliable, potentially compromising furnace efficiency or glass clarity. Similarly, in pharmaceutical excipient formulation, the molecular weight is used to establish exact ionic contributions. Hailei Chemical attaches a Certificate of Analysis to every shipment, confirming the assay against the theoretical molecular weightâgiving your quality team full confidence.
Beyond its molecular weight, potassium sulfate solubility in water is the most operationally critical physical property. K2SO4 dissolves endothermically, and its solubility shows a marked but manageable dependence on temperature.
| Temperature (°C) | Solubility (g K2SO4 / 100 g H2O) |
|---|---|
| 0 | 7.4 |
| 10 | 9.3 |
| 20 | 11.1 |
| 30 | 13.0 |
| 40 | 14.8 |
| 60 | 18.2 |
| 80 | 21.4 |
| 100 | 24.1 |
This moderate solubility, compared to highly soluble salts like potassium chloride, makes SOP especially suited for controlledârelease fertilizer blends and for applications where a steady, lowâconcentration potassium source is desiredâsuch as in foliar sprays or drip fertigation of premium greenhouse crops. It also explains SOPâs role as a refining agent in glass furnaces, where a precisely timed dissolution is needed to scavenge gaseous inclusions without creating refractory corrosion.
Buyers from aluminium recycling plants appreciate another facet: during the remelting of aluminium scrap, K2SO4 is used as a flux component to lower the melting point of oxide slag and improve metal recovery. The saltâs solubility curve guarantees that any residual flux on the recovered dross can be washed away with ambientâtemperature water, simplifying postâtreatment while keeping chlorideâinduced corrosion out of the system. When you buy potassium sulfate from Hailei Chemical, you receive material ground to your specified particle size, ensuring dissolution kinetics align with your specific process window.
The overwhelming volume of SOP is consumed by agriculture, where its low chloride index is unmatched. Understanding the molecular weight is essential for fertilizer formulators to calculate the K2O equivalent. K2O has a molecular weight of 94.20 g/mol, and one mole of K2SO4 (174.26 g) yields one mole of K2O. The theoretical K2O percentage is therefore (94.20 Ă· 174.26) Ă 100 = 54.0%. Our commercial product guarantees a minimum of 50% K2Oâa figure that accounts for small amounts of benign sulphate residuals and packagingârelated tolerances. Agricultural procurement teams use this conversion constantly when comparing SOP with potassium chloride (MOP) or potassium nitrate. Because SOP delivers both potassium and sulphur in the sulphate form, it simultaneously supports protein synthesis and enzyme activation without the osmotic stress that chloride can impose on sensitive root zones.
Agronomists calculate field application rates in kg K2O per hectare. With a guaranteed 50% K2O, a 100âkg sack of Hailei SOP delivers 50 kg of K2O. A recommended rate of 200 kg K2O/ha for a highâyield banana plantation therefore requires 400 kg of product per hectare. The same stoichiometric logic, rooted in the potassium sulphate molecular weight, empowers precise blending with monoammonium phosphate (MAP) and urea to create custom NPK grades without overâ or underâsupplying sulphur. This calculability reduces overâfertilisation risk and helps your downstream customers meet increasingly stringent environmental targets.
In the production of container glass, float glass, and specialty optical products, K2SO4 functions as a highâtemperature refining agent. Added in quantities typically ranging from 0.1 to 0.5 wt% of the batch, it decomposes above 1,100âŻÂ°C, releasing sulphur dioxide that helps homogenise the melt and eliminate bubbles. The molecular weight is used by furnace operators to calculate the exact SO2 yield per kilogram of refining agent. Given that one mole of K2SO4 yields one mole of SO2 (64.06 g), a 1,000âgram addition of pure SOP can theoretically release up to 367 grams of SO2. Predictability of this kind is invaluable when fineâtuning a furnace that operates 24/7. Hailei Chemical supplies SOP in controlled granular and powder forms to ensure safe handling and consistent metering into the batch house.
Secondary aluminium smelters face the constant challenge of minimising metal loss to dross while avoiding chlorideâbased fluxes that generate corrosive HCl fumes. Potassium sulphate provides a chlorideâfree alternative that improves slag fluidity by lowering the liquidus temperature of the oxide skin. Its moderate solubility also helps in subsequent dross leaching steps, allowing valuable aluminium residues to be recovered without aggressive chemical treatments. When buyers seek to buy potassium aluminum sulfateâoften confusing the twoâthey are typically looking for potash alum, which has a completely different chemistry (KAl(SO4)2·12H2O) and is used as a coagulant in water treatment, not as a slag conditioner. Understanding the chemical formula and molecular weight prevents such misâspecifications and ensures you procure exactly what your process demands.
Pharmacopoeiaâgrade potassium sulphate is used as an excipient in tablet formulations and as a component of mineral supplements. Here, the molecular weight is not a mere specification but a regulatory requirement. Monographs test for assay (typically 98.5â101.5% of theoretical K2SO4) and limit heavy metals, arsenic, and loss on drying. A product whose assay when tested against the 174.26 molecular weight falls outside this narrow window will be rejected. For pharmaceutical manufacturers, Hailei Chemical provides a dedicated lowâendotoxin grade screened through 200 mesh, supported by a full pharmacopoeial compliance dossier.
Procurement managers occasionally search for âalum potassium aluminum sulfateâ when they actually need potassium sulphate. While both chemicals supply potassium ions, their applications diverge sharply. Alum (potassium aluminum sulfate) is a double sulphate salt with a molecular weight of 474.39 g/mol (dodecahydrate) and a strong astringent taste; it finds use in water purification, leather tanning, and as a mordant in textile dyeing. By contrast, our potassium sulfate chemical formula K2SO4 yields a neutral pH, lowâreactivity salt ideal for chlorideâfree fertilisation and industrial fluxing. If your goal is to buy potassium aluminum sulfate, you will need a completely different specification sheet. This article focuses on potassium sulphate; for alum requirements, we recommend consulting a specialist supplier of aluminium salts.
The lesson is clear: always verify the chemical formula and molecular weight against your process requirement. When in doubt, request a sample and a certificate of analysis that quotes the assay relative to the theoretical molecular weight. Hailei Chemical welcomes such scrutiny and provides full technical documentation with every shipment.
Weifang Hailei Fine Chemical Co., Ltd. is one of Chinaâs foremost manufacturers and exporters of premium potassium sulphate. Our production capacity exceeds 100,000 metric tonnes per year, backed by onâsite quality laboratories that verify potassium sulphate molecular weight conformity, particle size distribution, chloride content, and heavy metal levels in accordance with ISO 9001:2015 standards. We export to over 55 countries, servicing major fertiliser blenders, containerâglass multinationals, secondary aluminium smelters, and pharmaceutical grade distributors.
Every container of Hailei potassium sulfate is accompanied by a detailed COA, a safety data sheet, and, for agricultural grades, a product stewardship card outlining solubility and handling best practices. Our supply chain team can arrange packaging in 25 kg, 50 kg, or 1000 kg jumbo bags, with options for palletised and shrinkâwrapped shipping to prevent moisture ingress. For pharmaceutical clients, we provide aluminiumâfoilâlined fibre drums and dedicated lot traceability.
By anchoring your procurement decision on technical fundamentalsâpotassium sulphate molecular weight, the potassium sulfate chemical formula, and potassium sulfate solubility in waterâyou mitigate quality risk and unlock the full performance potential of this versatile inorganic salt. Whether you need SOP for a tobacco fertilizer programme, a float glass line, or a pharmaceutical excipient application, Hailei Chemical is ready to partner.
Take the next step: request a tailored quotation or download our latest specification sheet. Our technical sales engineers will respond within one business day to discuss your required chemical parameters, packaging preferences, and delivery timeline. Letâs transform your molecularâweight knowledge into a reliable, costâeffective supply chain.