How to Choose Inorganic Acids: Making Descaling, Derusting, and Surface Treatment Controllable via pH and the “Fate of the Salts Formed” (with Tables 1–3)
How to Choose Inorganic Acids: Making Descaling, Derusting, and Surface Treatment Controllable via pH and the “Fate of the Salts Formed” (with Tables 1–3)
1.Real-World Problem: Scale/oxide-film buildup, and the two main action lines of inorganic-acid cleaning
In circulating cooling water, heat exchangers, boiler makeup water, acid pickling/cleaning, and metal surface treatment, many on-site headaches look highly similar: the longer a system runs, the more it tends to “get dirty”; once you enter the cleaning/maintenance stage, you often face a chain reaction where “the more you fix, the more troublesome it becomes.” Typical symptoms usually fall into three categories:
1. Scaling: deposition of calcium carbonate/carbonates, metal hydroxides, sulfates, etc. on surfaces
→ heat-transfer performance drops, pressure drop rises, energy consumption increases; in severe cases, local overheating and operational risk increase.
2. Rust/oxide films and corrosion-product coverage: iron oxides and mixed oxide films covering metal surfaces
→ reduces consistency in subsequent coating/plating/bonding processes; at the same time, deposits and films alter the interfacial micro-environment and may trigger localized failures such as pitting and crevice corrosion.
3. “They’re all acids, but performance differs dramatically”: even if you lower pH in the same way, some acids remove scale quickly and rinse away easily; others are more prone to induce corrosion, salt precipitation, or secondary deposition—sometimes making the problem even harder to handle.
To understand these phenomena, you need to grasp the two most fundamental action lines of inorganic acids in aqueous systems:
1. Providing H⁺ (manifesting as H₃O⁺ in water) to shift equilibria: driving deposits such as carbonates/hydroxides toward dissolution, and affecting oxide-film-related dissolution–transformation processes. This is the “acidity axis.”
2. Determining what the deposits ultimately become—and whether they can be carried away: inorganic acids do more than “lower pH.” Their anions and the system environment influence the transformation pathway of deposits—whether they become forms that are more soluble/more dispersible/more easily detached and flushed out, or whether under certain conditions they form sparingly soluble salts that re-deposit. Meanwhile, they can markedly change the corrosion window of metals and the difficulty of matching inhibitors/corrosion-control packages.
2.What Are Inorganic Acids: Definition and common scope
2.1 The chemical definition of “acid”
The general IUPAC (Gold Book) definition: an acid can be
1. a species that donates a hydron (i.e., H⁺-type hydrogen cations) (Brønsted acid), or
2. a species that accepts an electron pair and forms a coordinative/covalent-type interaction (Lewis acid).
In aqueous solution, hydron does not persist long-term as “bare H⁺”; acidity is expressed as H₃O⁺ and more strongly hydrated clusters. Therefore, in engineering discussions it is often more faithful to real systems to say “provides H⁺ (manifesting as H₃O⁺/hydrated hydrogen ions in water).”
Two common “sources of acidity”:
1. Most common in aqueous systems: Brønsted acids (hydron donors)
These directly set solution acidity (pH/acidity window) and shift dissolution–deposition–transformation processes by changing equilibria.
2. Common in nonaqueous/coordination chemistry: Lewis acids (electron-pair acceptors)
For example, AlCl₃ and BF₃ do not express acidity by “releasing H⁺,” but by acting as electron-pair acceptors to form adducts/coordination structures with Lewis bases.
2.2 What do “inorganic acids / mineral acids” usually refer to?
“Inorganic acids” are often used roughly interchangeably with “mineral acids.”
In water treatment, acid pickling, and bulk chemical-industry discussions, the most commonly implied “core four” are typically:
a) hydrochloric acid (HCl), sulfuric acid (H₂SO₄), nitric acid (HNO₃), phosphoric acid (H₃PO₄).
In a broader “mineral/inorganic acid” list, hydrofluoric acid (HF) and perchloric acid (HClO₄) are also often included (because they are likewise common inorganic-origin acids and are widely used industrially, with characteristic risk windows).
Two reminders to avoid misuse:
1. “Contains carbon” ≠ “organic acid”: for example, carbonic acid (H₂CO₃) contains carbon, but it is often discussed within inorganic/water-chemistry contexts (especially for carbonate equilibria, scaling, and alkalinity).
2. “Inorganic acid” ≠ “strong acid”: inorganic-origin acids span a wide range of strengths. In engineering selection, what truly governs performance is often “the right acidity range + the anion / fate of salts formed + corrosion and secondary-deposition risks,” rather than the single label “inorganic acid.”
3.Why Inorganic Acids Remove Scale/Films: the three most common mechanisms
Mechanism (A/B/C) | What it mainly solves | Typical reactions/phenomena | Common deposits / suitable targets |
A. Use H⁺ to drive the solid phase back into the aqueous phase (dissolution/descaling) | Use acidity to convert sparingly soluble deposits into ionic/soluble forms, making them “come off the surface” and enter the water phase | Calcium carbonate scale: CaCO₃(s) + 2H⁺ → Ca²⁺ + CO₂↑ + H₂O; Hydroxide deposits (general form): M(OH)ₙ(s) + nH⁺ → Mⁿ⁺ + nH₂O; (Oxides often appear as “acid + water → metal ions + water”) | CaCO₃/carbonate scale; hydroxides such as Fe(OH)ₓ, Al(OH)₃; some oxides/rust products |
B. The anion determines the “fate of the salts formed” (soluble vs secondary deposition vs residue) | Even with the same H⁺ supply, different acid anions drive different product pathways: whether salts are soluble, whether they re-deposit, whether hard-to-rinse residues remain, and whether downstream processes are interfered with | Example: CaCO₃ + 2HCl → CaCl₂(aq) + CO₂ + H₂O (salts are usually soluble and easy to carry away); but in Ca-containing systems, using sulfuric acid may more readily lead to sparingly soluble salts like CaSO₄, creating secondary-deposition risk (depends on concentration/temperature/ionic strength/residence time) | Most typical in calcium-salt scaling systems; also includes salts/complex forms formed after Fe, Cu, etc. dissolve and interact with system anions |
C. Rewrite the interfacial film → simultaneously rewrite corrosion risk and the workable operating window | Once an oxide/passive film is dissolved, damaged, or re-formed, the electrochemical state changes: corrosion may become easier, or re-passivation may occur under suitable conditions | Example: stainless steel relies on an ultrathin passive film for corrosion resistance; in environments containing Cl⁻ and similar species, localized film breakdown is more likely, increasing pitting/crevice-corrosion risk (risk strength is strongly correlated with temperature, Cl⁻ activity, stagnation/under-deposit microenvironments, etc.) | Stainless steel, copper alloys, carbon steel, and other material systems whose corrosion resistance is “film-controlled” |
Note: oxide/passive-film solubility varies widely. Rust and some metal oxides can be dissolved by strong acids, but SiO₂ is extremely difficult to dissolve in non-fluoride acids; some dense films require “fluoride / reducing / complexing” conditions to accelerate dissolution markedly.
4.Three common ways to classify inorganic acids
Classification key (dimension) | How to classify | Representative examples | Why it matters |
A. Structural type (whether it contains O) | Hydracids (oxygen-free acids): no O in the molecule (typical HX); Oxoacids: acidic group contains O (typical HₙXOₘ) | Hydracids: HCl, HBr, HI, HF; Oxoacids: H₂SO₄, HNO₃, H₃PO₄, HClO₄ | Structure often governs: (i) trends in acid strength; (ii) differences in salt forms; (iii) whether “side-pathways” such as oxidizing behavior, film formation, or secondary deposition are more likely (final outcome still depends on concentration, temperature, and ionic environment) |
B. Strength in water (degree of dissociation) | Strong acids: (nearly) completely dissociate in water; Weak acids: only partially dissociate | Strong acids: HCl, HNO₃, H₂SO₄, HClO₄, HBr, HI; Weak acids: HF (often classified as a weak acid in water) | Determines how much H₃O⁺ is available at the same concentration, affecting descaling rate and acid consumption; also influences whether buffering/“gentler control” is easier (weak acids/polyprotic systems can sometimes be controlled more mildly) |
C. Additional chemistry (beyond “donating H⁺”) | Classify mainly by whether additional reactions/material effects are introduced: oxidizing ability, strong complexation/etching behavior, and process-relevant traits (volatility/residue, tendency for secondary deposition, etc.) | Nitric acid: strong oxidizer character (especially concentrated HNO₃ / under specific conditions), introducing oxidative side reactions and distinct material behavior. HF: often classified as a weak acid, but fluoride chemistry is highly special; it can etch/dissolve SiO₂ and can cause deep tissue damage and systemic toxicity risks | This is key to explaining “same pH drop, very different outcomes”: different acids may push the system into entirely different pathways—oxidative side reactions, passivation/depassivation, increased sensitivity to localized corrosion, or salts that are harder to remove and re-deposit |
Small reminders:
1. “Strong/weak” is a statement in water, and solvent effects exist: the apparent strength of the same acid can change in different solvents.
2. Weak acid ≠ safer: HF is often called a weak acid, yet it is highly special from a safety standpoint (deep penetration and potential systemic poisoning).
3. H₂SO₄ is generally treated as a strong acid; it is a diprotic acid: the first dissociation is very strong, while the second is significantly weaker. The second-step dissociation (HSO₄⁻ → SO₄²⁻) is not “complete”; at high concentration/high ionic strength, it should be handled via system-specific calculation.
5.What Problems Do Inorganic Acids Solve in “Descaling / Pickling / Surface Treatment”?
Scenario | Main pain point | Core problem that inorganic acids solve | Notes / precautions |
Water scale / carbonate deposits (heat exchangers, piping, cleaning) | Lower heat transfer, blockage, higher energy consumption | Use H⁺ to drive carbonates back into the aqueous phase and convert deposits into forms that can be flushed away | Don’t judge only by “how strong the acid is.” Also evaluate whether the salts formed are highly soluble, and whether they may re-precipitate / cause secondary deposition |
Rust / oxide films (acid pickling, pretreatment) | Surfaces covered by oxides, harming consistency in coating / plating / bonding | Dissolve oxides/hydroxides so the surface returns to a processable state | While removing films, you may cause over-etching / roughening, and push the material into conditions more prone to localized corrosion (needs inhibitors and process control) |
Stainless steel / alloy systems in chloride-containing environments | Higher pitting/crevice-corrosion risk; more sensitive under deposits | Acids can remove deposits/contaminants; but for stainless steel the key is whether the passive film is damaged and whether it can be restored | The key is not “using acid to cure pitting,” but avoiding driving the system into a more sensitive regime: evaluate Cl⁻ sources (does the acid introduce Cl⁻?), temperature, stagnation/crevices and under-deposit microenvironments, plus oxidizing strength and repassivation conditions. Reference comparison: stainless-steel passivation / free-iron removal commonly uses nitric acid or citric-acid systems (e.g., ASTM A967). Acid systems containing Cl⁻ are generally not used for passivation and require greater caution. |
Glass / silicon-material processing | Need etching/polishing/frosting of SiO₂ surfaces | Relies on the unique chemistry of fluoride-containing systems—not merely supplying H⁺, but crucially F⁻-driven reactions | HF is hazardous: do not underestimate its harm or PPE/controls simply because it is “relatively weak in water” |
6.The Value of Inorganic Acids Goes Beyond Cleaning: Three Key Application Classes
Even without discussing descaling, pickling, or surface treatment, inorganic acids remain a foundational, largely irreplaceable class of “universal inputs” in modern industry—mainly in three ways:
1. Bulk base feedstocks for chemical manufacturing
Taking sulfuric acid as a representative example, inorganic acids are not only massive-volume industrial products themselves, but also upstream inputs for many critical chemical and materials value chains—widely serving fertilizer-related chemicals, petroleum refining, and multiple manufacturing sectors.
2. Acid catalysis and process control (measurable, reproducible acidity / pH)
Many reactions and processes are highly sensitive to acidity: reaction rate, selectivity, side reactions, and impurity profiles often shift markedly with the acidity window. Inorganic-acid systems are advantageous because they provide strong, measurable acidity and can be supplied stably, so they are commonly used as acid-catalyst sources or as pH/acidity control tools to pull processes back into a controllable operating range.
3. “Basic consumables” for materials and electronics manufacturing: cleaning, surface activation, and impurity control
In materials/electronics manufacturing, inorganic acids (commonly various combinations and grades of sulfuric/hydrochloric/nitric/phosphoric systems) are widely used for wet cleaning, removal of metal contamination, surface activation/pretreatment, and process-consistency control. The “irreplaceable” point here is not simply “acid strength,” but high purity, traceability, and stable supply, which directly support yield and consistency. (A small number of special etch processes introduce more specialized acid systems and should be discussed on a process-by-process basis.)
7.Inorganic-Acid-Related Chemicals | Quick “Pick-the-Right-Table” Navigation by Research Task (Tables 1–3)
Research task / experimental scenario | Which table to check first | Why this table first |
Routine acidification / pH adjustment, sample pretreatment (general inorganic samples/salts), salt formation (turning an amine/base into a salt) | Table 1 | Table 1 focuses on the most commonly used basic strong acids and hydrohalic acids (HCl/H₂SO₄/HNO₃/HBr/HI/HF/HClO₄), covering the main line of “acidity source + anion/halogen introduction,” making it best for baseline selection. |
Sample digestion / pretreatment for elemental analysis (especially trace-metal-sensitive work), requiring cleaner background or standardized-grade reagents | Table 1 | Table 1 includes analytical/trace-controlled options (e.g., Hg-controlled fuming HCl, PrimorTrace™ HI), which better match digestion–analysis needs for impurity background and consistency. |
Nitration (mixed acid), strong-acid catalysis needing high acidity, or driving equilibria via dehydration (esterification/condensation, etc.) | Table 1 | The H₂SO₄/HNO₃ combination and strong-acid dehydration behavior are typical “mineral-acid process” features; most nitration/strong-acid-catalysis routes begin with conditions covered in Table 1. |
SiO₂/silicate-related work: glass/quartz etching, silicate mineral digestion, silicon-containing surface cleaning | Table 1 (priority) → Table 3 (if complexing acids are needed) | HF is the primary entry point (Table 1). If you need fluoride-complexing/salt systems (e.g., fluosilicate-related), then go to Table 3 to complete the “fluoride-complexing acids” set. |
Buffer / phosphate systems (formulations, method development, controllable pH windows), or acidifying HPLC mobile phases | Table 2 | Table 2 is a consolidated “phosphate-family” set: phosphoric acid (HPLC grade), polyphosphoric/pyrophosphoric/phosphorous acids—best for selection from buffering–complexation–condensation perspectives. |
Driving reactions with condensed phosphoric acids / strongly dehydrating acid media (dehydrative condensation, cyclization/acylation promotion, etc.), or exploring phosphorus-containing intermediate routes | Table 2 (polyphosphoric / pyrophosphoric / phosphorous acids) | These tasks depend on “acid + dehydration/condensation capability + complexation/salt behavior.” Table 2 places condensed-phosphate reagents together for fast side-by-side comparison. |
Metal-ion complexation/stabilization (lowering free-metal activity for stability controls), or preparing/benchmarking pyrophosphate/phosphite salts | Table 2 | Pyrophosphoric/phosphorous acids are common entry points for “coordination/reducing-type phosphorus acids,” making complexation stabilization and salt preparation more direct. |
Oxidative cleavage of vicinal diols in glycans/polysaccharides/glycoproteins; electrophoresis-related oxidation/labeling steps (e.g., staining/analysis systems) | Table 3 | This is a “selective oxidizing acid” route. Periodic acid is the most typical entry point, and Table 3 groups these specialized functional acids. |
Need a Se source (selenites/Se-containing materials, electrochemistry/surface systems) with sensitivity to metal impurities | Table 3 | Selenous acid (PrimorTrace™) is a “functional inorganic acid / element source,” closer to materials/electrochemistry selection than routine acidification—Table 3 fits better. |
Need strong Brønsted-acid catalysis or heteropoly-acid-related work: catalyst screening, proton conductors/functional additives, analytical precipitation/color development | Table 3 | Phosphotungstic/silicic tungstic acids (heteropoly acids) are “strong acid sites + possible redox behavior” functional-acid systems; typically you compare/screen them directly from Table 3. |
Descaling/pickling formulations (heat exchangers, boilers, metal descaling/derusting) and you want solid acids for more controllable handling | Table 3 | Sulfamic acid is a typical stable solid acid; its engineering-cleaning and formulation use cases are more concentrated in Table 3. |
Need tetrafluoroborate (BF₄⁻) for salt formation / ionic liquids / electrolytes, or for electroplating/surface-treatment electrolytes (want to avoid Cl⁻) | Table 3 | Fluoroboric acid is a “fluoride complexing acid / specific anion source,” ideal for salt-form switching and electrolyte needs—Table 3 is more direct. |
Need fluosilicate systems, fluoride complexation / fluorination process evaluation (industrial fluoride formulations) | Table 3 | Fluorosilicic acid is a classic “complexing fluoride acid + salt-system entry,” more of a dedicated system than a general-purpose acid. |
Strong sulfonation / chlorosulfonation to introduce –SO₃H / –SO₂Cl (making sulfonic acids, sulfonyl chlorides, sulfonamides, etc.) | Table 3 | Chlorosulfonic acid is a reactive reagent, not routine acidification; its pathway is highly specialized, so Table 3 is the right place to look. |
Chromium(VI) oxidation systems (oxidative activation / synthetic oxidation), requiring chromic acid/dichromate entry points | Table 3 | Cr(VI) oxidants are “high-risk strong-oxidation feedstocks,” typically treated as specialized oxidizing-system selection rather than grouped with basic mineral acids—Table 3 matches. |
Not sure where to start: you only know “I need an inorganic acid,” but haven’t decided whether it’s for acidification/sulfonation/oxidation/buffering/element sourcing | Table 1 first → then Tables 2/3 | Use Table 1 to decide whether a “basic strong acid / hydrohalic acid” solves it. If it’s more like “systematic buffering/condensation/complexation,” switch to Table 2. If it’s “special functional reagents/element sources/heteropoly acids/sulfonating agents/fluoride complexing acids,” switch to Table 3. |
Table 1｜Basic Strong Acids & Hydrohalic Acids (Acidification / Digestion / Salt Formation / Etching / Nitration / Oxidation)
Category | CAS No. | Aladdin Cat. No. | Product name | Grade or purity | Key features & applications |
Hydrohalic acid｜Hydrochloric acid (acidification/digestion/salt formation) | 7647-01-0 | H485680 | Fuming Hydrochloric Acid, 37% (controlled precursor chemical) | Premium grade, suitable for analysis, max. 0.001 ppm Hg | High-concentration aqueous HCl (fuming type): used for sample acidification, dissolution of inorganic/metal oxides and analytical digestion, preparation of chloride salts / salt formation, and acid washing of equipment and labware (trace-Hg control benefits trace analysis). Note its volatility and strong corrosivity; ensure ventilation and corrosion-resistant materials. |
Basic mineral acid｜Sulfuric acid (strong acid/dehydrating/catalysis) | 7664-93-9 | S485807 | Sulfuric Acid (controlled precursor chemical) | Premium grade, suitable for analysis, ≥98% | Typical strong acid and dehydrating agent: used in acid-catalyzed reactions such as esterification/hydration, preparation of nitration “mixed acid,” sample digestion, and pickling/cleaning. Highly concentrated acid strongly dehydrates organics and releases significant heat; temperature and addition rate must be controlled during scale-up and dosing. |
Oxygen-containing strong acid｜Nitric acid (strong acid/oxidation/nitration) | 7697-37-2 | N116238 | Nitric Acid (explosives precursor) | Premium grade, 65–68% | Strong acid with oxidizing power: used for nitration, surface treatment and dissolution of metals/alloys, sample digestion (including trace-element pretreatment), and preparation of nitrates. Reacts violently with organics/reducing agents; requires strict segregation and safety management. |
Fluorine-containing inorganic acid｜Hydrofluoric acid (complexation/SiO₂ etching) | 7664-39-3 | H116232 | Hydrofluoric Acid | Premium grade, ≥40% | Highly corrosive fluoride acid: characteristic dissolution/etching of SiO₂/silicates (glass/quartz etching, semiconductor/surface cleaning, mineral-sample digestion). Also forms stable fluoride complexes for inorganic synthesis and separations. Extremely toxic/high hazard—requires dedicated protection and calcium/magnesium emergency response measures. |
Oxygen-containing strong acid｜Perchloric acid (superacid/strong oxidizer) | 7601-90-3 | P433647 | Perchloric Acid (explosives precursor) | For analysis (max. 0.0000005% Hg), premium grade, ACS/ISO/Reag., European Pharmacopoeia | Superacid with strong oxidizing power: used for perchlorate preparation and for analysis/digestion under strong-acid conditions and trace-metal pretreatment (ultra-low Hg supports trace control). Significant hazard when contacting organics/combustibles—use a dedicated perchloric-acid fume hood and compliant procedures. |
Hydrohalic acid｜Hydroiodic acid (strong acid/reduction/iodination) | 10034-85-2 | H320059 | Hydroiodic Acid | PrimorTrace™, ≥99.999% metals basis, distilled, 57 wt.% | Strong acid plus strongly nucleophilic I⁻/reducing system: used for iodide preparation, ether cleavage (to iodoalkanes / alcohol-related transformations), and exploring certain reduction/deoxygenation routes. PrimorTrace™ low-metal background suits trace-metal-sensitive systems and high-purity route benchmarking. |
Hydrohalic acid｜Hydrobromic acid (strong acid/bromination/cleavage) | 10035-10-6 | H116385 | Hydrobromic Acid | AR, ~40% | Strong acid and bromide source: used to prepare bromide salts / salt formation, ether cleavage and bromoalkane preparation, and acid-catalyzed hydrolysis/rearrangements. In pharma intermediates and materials synthesis, it is often used as an integrated “bromine source + acid” reagent for route screening. |
Table 2｜Phosphoric-Acid Systems (Buffering / Condensation / Complexation / Reducing Phosphorus Acids)
Category | CAS No. | Aladdin Cat. No. | Product name | Grade or purity | Key features & applications |
Phosphoric-acid system｜Poly/condensed phosphoric acids (strong dehydrating medium) | 8017-16-1 | Polyphosphoric Acid | ~105% H₃PO₄ | High-viscosity “strongly dehydrating acidic medium”: commonly used for dehydrative condensation and promoting cyclization/acylation (e.g., intramolecular cyclizations of less reactive substrates), building polyphosphate/phosphoric-anhydride systems, and preparing phosphorus-containing intermediates. Also used as a strongly acidic reaction solvent/catalytic medium for process exploration. (Note: “105%” is a label calculated on a P₂O₅ basis, indicating a higher degree of condensation/dehydration than 100% phosphoric acid; it does not literally mean “>100% concentration.”) | |
Phosphoric-acid system｜Phosphoric acid (buffering/HPLC acidification) | 7664-38-2 | Phosphoric Acid | Chromatographic HPLC grade, ≥85% | HPLC-grade acidifier and base acid for buffers: commonly used to acidify mobile phases (improve peak shape/suppress tailing/control ionization), prepare phosphate buffer systems, and develop analytical methods; also used in inorganic salt preparation and in phosphating/surface-treatment research. | |
Phosphoric-acid system｜Condensed phosphoric acid (complexation/buffering/salt prep) | 2466-09-3 | Pyrophosphoric Acid | Moligand™, ≥95% (H₄P₂O₇ basis) | Representative condensed phosphoric acid: used to prepare pyrophosphates, complex/stabilize metal ions (reduce free-metal activity), and study buffering/formulation systems. Moligand™ labeling supports use as a “coordination/complexation capability” benchmark for evaluating process windows and stability. | |
Phosphoric-acid system｜Phosphorous acid (reduction/phosphite precursor) | 13598-36-2 | Solid Phosphorous Acid | AR, ≥99% | H₃PO₃, a reducing-type phosphorus acid: commonly used to prepare phosphites and as a precursor for phosphonates (P–C systems); also serves as a mild reducing agent and antioxidant/stabilizing component. In electroplating/electroless plating and materials systems, it is often used as a reduction/formulation variable for comparative studies. |
Table 3｜Functional Inorganic Acids & Dedicated Systems (Heteropoly acids / Fluoride-complexing acids / Selective oxidation / Solid acids / Sulfonating agents, etc.)
Category | CAS No. | Aladdin Cat. No. | Product name | Grade or purity | Key features & applications |
Weak acid / buffering｜Boric acid (boron source/buffer/biochemical) | 10043-35-3 | Boric Acid | For cell culture, for insect cell culture, ≥99.5% | Mild inorganic weak acid and boron source: used for borate buffer systems, fine-tuning pH/ionic strength in formulations, and as a precursor for glass/ceramics and boron-containing materials. In biochemical/cell-culture contexts, can serve as a boron source and formulation additive (e.g., insect cell-culture formulation research). | |
Selective oxidizing acid｜Periodic acid (vicinal-diol cleavage) | 10450-60-9 | Periodic Acid | For electrophoresis, ≥99% | Classic selective oxidant: cleaves 1,2-diols and glycans via oxidative scission (Malaprade reaction); widely used for oxidative labeling of polysaccharides/glycoproteins and for staining systems in electrophoresis-related workflows. High purity helps control background and improve reproducibility. | |
Oxoacid｜Iodic acid (oxidation/iodate source) | 7782-68-5 | Iodic Acid | Chemical Pure (CP), ≥99.5% | Stable iodate source and oxidizing inorganic acid: used to prepare iodates and iodide–iodate systems, as a reference in analytical titration/redox benchmarking, and to explore mild oxidative conditions in synthesis. High purity helps reduce interference from inorganic impurities. | |
Oxoacid｜Selenous acid (Se source/redox) | 7783-00-8 | Selenous Acid | PrimorTrace™, ≥99.999% metals basis | Important selenium source and redox reagent: used to prepare selenites and selenium-related inorganic salts, and to introduce Se sources in materials/electrochemical and surface-treatment contexts. In some systems it can participate in mild redox processes. High purity/low metals suits materials and plating/electrochemistry studies sensitive to metal impurities. | |
Sulfur-containing functional acid｜Sulfamic acid (solid acid/descaling) | 5329-14-6 | Sulfamic Acid | Suitable for analysis, premium grade | Stable, non-volatile solid acid: commonly used for descaling/derusting cleaning (boilers, heat exchangers, metal surfaces), pickling formulations, and pH adjustment; also used to prepare sulfamate salts/sulfonamide-related intermediates and as an additive in plating/surface-treatment systems. | |
Heteropoly acid｜Phosphotungstic acid (strong acid/catalysis/analysis) | 12501-23-4 | Phosphotungstic Acid Hydrate | Suitable for analysis, premium grade | Tungsten-based heteropoly acid (strong Brønsted acid + redox activity): used as an acid catalyst (condensation, esterification, alkylation, etc.), as an analytical precipitating/chromogenic reagent (e.g., for biomacromolecules/alkaloids), and as a proton conductor/functional additive in materials. The hydrate form facilitates solution preparation for method evaluation. | |
Heteropoly acid｜Silicotungstic acid (strong acid/catalysis/analysis) | 12027-43-9 | Silicotungstic Acid Hydrate | Suitable for analysis, premium grade | Typical silicotungstic heteropoly acid: used for strong-acid catalysis and heteropolysalt preparation, analytical precipitation/qualitative systems, and as a strong-acid/proton-conduction component in functional materials. Suitable as a “strong-acid site” benchmark for catalyst screening. | |
Fluoride-complexing acid｜Fluorosilicic acid (fluorination/etching/salt prep) | 16961-83-4 | Fluorosilicic Acid | GR, 30.0–32.0% | Typical fluoride-complexing acid: used to prepare fluorosilicates, for treatment of certain glass/silicate systems and etching-related research, and for evaluating industrial fluoride-formulation systems. Aqueous-solution grade supports dosing and concentration control, but it is strongly corrosive and requires fluoride-resistant materials and compliant protection. | |
Fluoride-complexing acid｜Fluoroboric acid (BF₄⁻ source/electroplating/salt formation) | 16872-11-0 | Fluoroboric Acid | AR, ≥40% | Strong acid providing BF₄⁻: used to prepare tetrafluoroborate salts (salt-form switching, ionic liquids/electrolytes), electroplating/surface-treatment electrolytes, and certain inorganic syntheses (often chosen to avoid introducing chloride). The aqueous form enables convenient concentration and dosing control. | |
Strongly oxidizing Cr(VI) acid system｜Chromic anhydride/oxidant | 1333-82-0 | Chromium(VI) Oxide | Suitable for synthesis, ≥99% | Core feedstock for Cr(VI) oxidation systems: used to prepare chromic acid/dichromate oxidation media (e.g., alcohol → aldehyde/ketone/acid), surface cleaning/oxidative activation, and some materials surface treatments. Cr(VI) is highly toxic and carcinogenic; waste handling and PPE must comply strictly with regulations. | |
Sulfonating agent｜Chlorosulfonic acid (strong sulfonation/chlorosulfonation) | 7790-94-5 | C684374 | Chlorosulfonic Acid | ≥99% | Highly reactive sulfonating/chlorosulfonating reagent: used to introduce –SO₃H or –SO₂Cl (to make sulfonic acids, sulfonyl chlorides, and downstream sulfonamides/sulfonate esters), common in dye, surfactant, and pharma-intermediate routes. Strongly exothermic and reacts violently with water; requires strictly anhydrous conditions and low-temperature controlled addition. |
Note: The items above are representative Aladdin products. For additional specifications, please refer to the product list at the end of the document, or search the Aladdin website using “product name / CAS / catalog number.”