laboratory chemicals

Calcium iodide (CaI₂) is a white to pale yellow, hygroscopic crystalline solid formed by the ionic bonding of calcium (Ca²⁺) and iodide (I⁻) ions in a hexagonal or rhombohedral lattice.​ Properties It has high water solubility (66–121 g/100 mL at 20°C), density around 3.96 g/cm³, melting point 779°C, and boiling point ~1100°C; it is also soluble in alcohols and acetone but reacts with CO₂ in air to form calcium carbonate and iodine.​ Production Prepared by neutralizing calcium carbonate, oxide, or hydroxide with hydroiodic acid, or by direct reaction of calcium metal with iodine gas at 200–400°C, followed by purification to remove moisture sensitivity.​ Main uses Employed as a reagent in analytical chemistry, photography, and pharmaceutical preparations; also used in organic synthesis as a catalyst or reducing agent, though limited industrially due to instability in moist air.​

Calcium hypochlorite stabilized (35% Cl) is a white or pale grayish granular or powdered solid (Ca(ClO)₂), formulated with stabilizers like calcium carbonate or silicates to prevent decomposition and deliver approximately 35% available chlorine for disinfection.​ Properties It has high water solubility (21 g/100 mL at 20°C), density around 2.35 g/cm³, decomposes above 100°C releasing oxygen and chlorine, and acts as a strong oxidizer and base, producing hypochlorous acid (HOCl) in water for biocidal action.​ Stabilization and production Stabilizers reduce sensitivity to moisture, heat, and organics; produced industrially by chlorination of calcium hydroxide slurry with chlorine gas (3Cl₂ + Ca(OH)₂ → Ca(ClO)₂ + 2HCl), then dried and blended.​ Main uses Widely applied as a bleaching agent, pool/spa sanitizer (70–200 ppm dosing), water treatment disinfectant, and laundry bleach; preferred over sodium hypochlorite for its stability, non-liquid form, and lack of sodium addition.​

Calcium hypochlorite solution is an aqueous preparation of Ca(ClO)₂, typically 5–15% active chlorine equivalent, used as a liquid disinfectant and bleach with enhanced stability over sodium hypochlorite in certain conditions.​ Composition and properties It contains dissolved calcium hypochlorite (often stabilized with lime or silicates), releasing hypochlorous acid (HOCl) in water for biocidal action; pH is alkaline (10–12), less stable than solid form but easier to dose, with density ~1.1–1.2 g/mL and chlorine odor.​ Preparation Produced by dissolving granular calcium hypochlorite in water under controlled conditions to avoid decomposition, or via electrolysis/chlorination of calcium hydroxide solutions; commercial solutions are filtered and buffered.​ Main uses Applied in water treatment (swimming pools, potable water), sanitation, laundry bleaching, and food processing; preferred where calcium addition is beneficial, though it increases water hardness unlike NaOCl.

Calcium hydroxide extra pure is a high-purity grade of Ca(OH)₂, supplied as a fine white, amorphous powder with assay ≥94–98%, minimal impurities (e.g., Cl ≤0.04%, SO₄ ≤0.4%, heavy metals ≤0.005%), and clarity in acid solution for analytical reliability.​ Properties It is sparingly soluble in water (0.185 g/100 mL at 0°C, increasing with temperature), with pH ~12.4 in solution, density 2.24 g/cm³, and decomposes at ~580°C without melting; odorless and hygroscopic.​ Production Prepared by slaking quicklime (CaO) with controlled water addition, aging the suspension, then washing, filtering, and drying to meet extra pure specs; high purity minimizes iron and alkali salts.​ Main uses Serves as a lab reagent for acid neutralization, calcium standard in titrations, pH buffer in formulations, and precursor in cement/chemical synthesis; ideal for pharma, food (E526), and water treatment due to low contaminants.​

Calcium hydrogen phosphate (CaHPO₄), also known as dicalcium phosphate or dibasic calcium phosphate, is a white, odorless crystalline powder used as a calcium and phosphorus supplement.​ Properties It occurs as anhydrous (density 2.89 g/cm³) or dihydrate (CaHPO₄·2H₂O) forms, sparingly soluble in water (~0.02 g/100 mL), soluble in dilute acids, with pH 7–8 in suspension and decomposition above 370°C to form calcium pyrophosphate.​ Production Prepared by reacting phosphoric acid with calcium hydroxide or carbonate under controlled pH (around 4–6), precipitating the dihydrate, then optionally dehydrating at 60–70°C for the anhydrous form.​ Main uses Functions as a food additive (E341(ii)) for fortification, dough conditioner, and anticaking agent; in animal feed, toothpaste abrasive, pharmaceuticals (tablets), and as a precursor in fertilizers or ceramics.​

Calcium formate extra pure is a high-purity grade of Ca(HCOO)₂, supplied as a white to off-white crystalline powder with assay ≥97.5%, low impurities (e.g., heavy metals ≤10 ppm, Cl ≤0.1%), and confirmed infrared spectrum for analytical and lab use.​ Properties It is odorless, with solubility ~17 g/100 mL in water at 20°C (increasing with temperature), density ~1.59–2.02 g/cm³, melting point ~300°C (decomposes), and pH ~7–8 in solution; stable under normal conditions but hygroscopic.​ Production Formed by reacting calcium hydroxide or carbonate with formic acid, followed by filtration, purification, and drying; extra pure grades ensure batch consistency via titration and spectroscopic verification.​ Main uses Acts as a cement/concrete accelerator (shortens setting time), lab reagent for calcium analysis, food additive (E238, limited), and in leather tanning or animal feed; high purity suits precise formulations without contaminants.

Calcium fluoride 99% (CaF₂) is a high-purity, white crystalline powder or cubic single crystals with ≥99% assay, minimal impurities (e.g., heavy metals <10 ppm), and exceptional optical transparency from UV (140 nm) to mid-IR (8 µm).​ Properties It has low water solubility (0.0016 g/100 mL), density 3.18 g/cm³, melting point 1418°C, refractive index ~1.43, and high resistance to thermal shock and radiation; chemically inert to most acids except HF.​ Production Purified from natural fluorite (CaF₂ ore) via flotation, acid leaching, and recrystallization, or synthesized by reacting CaCO₃ with HF; 99% grade ensures low birefringence for optics.​ Main uses Essential for optical components (lenses, prisms, windows) in spectroscopy, lasers, UV lithography, and IR imaging; also as flux in ceramics/metallurgy, HF precursor, and in dental composites for fluoride release.