Ammonium Iodate CAS 13446-09-8 99% white crystalline powder oxidizing agent / analytical reagent and inorganic iodate

1. Product Overview

Ammonium Iodate (Iodic acid (HIO₃), ammonium salt (1:1); CAS 13446-09-8; molecular formula H₄INO₃ / NH₄IO₃; MW 192.94) is an inorganic ammonium salt of iodic acid. It appears as white to off-white crystalline powder or colorless rhombic/monoclinic crystals. Slightly soluble in cold water (~2.6 g/100 mL at 20 °C), practically insoluble in ethanol and hot water. Decomposes on heating at ~150 °C (dec.) to release iodine, oxygen, and ammonia; in acidic media it is a moderately strong oxidant and reacts quantitatively with iodide to liberate iodine (used in iodometric titrations). Supplied at ≥99% purity (Reagent/AR grade), it is primarily used as an analytical reagent for iodometric determinations, a laboratory oxidant, a source of iodate ions in inorganic synthesis, and a reference standard in analytical chemistry. Moisture-sensitive and light-sensitive; store dry, cool, and protected from combustibles. For laboratory/research/analytical use only; not for human/veterinary therapeutic application.

2. Key Features and Advantages

• High purity ≥99% (Reagent/AR), low chloride and heavy-metal impurities, suitable for precise iodometric titrations and quantitative analysis.

• Moderate oxidizing power in acidic medium: IO₃⁻ + 5I⁻ + 6H⁺ → 3I₂ + 3H₂O, enabling standard iodate–iodide redox methods for determining ascorbic acid, thiosulfate, sulfites, etc.

• Sharp decomposition at 150 °C (dec.), useful as a controlled thermal source of iodine vapor in lab demonstrations and calibration.

• White crystalline form with good handling characteristics; dissolves slowly in cold water to give neutral/clear solution (pH ~5–6 due to slight hydrolysis).

• Stable as dry powder under recommended storage (dry, cool, dark); compatible with glass/PTFE ware, avoid organics and reductants.

• Available in reagent packs (100 mg–1 kg) and bulk (5 kg/25 kg drums for industrial analytical prep).

3. Main Applications

• Analytical chemistry: primary standard/secondary standard for iodometric titrations (determination of ascorbic acid, thiosulfate, sulfite, sulfide, peroxides); used to prepare iodate–iodide starch indicator solutions.

• Laboratory oxidant: mild to moderate oxidant in acidic aqueous media for organic/inorganic redox reactions, e.g., oxidation of thiols, sulfites, and certain metals.

• Inorganic synthesis: source of IO₃⁻ anion for precipitating insoluble metal iodates (Ba(IO₃)₂, Pb(IO₃)₂) in solubility studies and gravimetric analysis.

• Educational/demo use: controlled thermal decomposition to generate iodine vapor (purple fumes) in teaching labs; used in redox demonstration kits.

• Photographic/imaging R&D (historical): minor role as an iodate source in alternative photographic emulsions and sensitizers (research only).

• Reference material: used by standards labs for calibrating iodometric methods and as a pure iodate source for method validation.

4. Technical Specifications

5. Storage and Handling

Store as dry powder in a tightly sealed, light-resistant container (amber bottle or foil-wrapped) at 15–25 °C in a cool, dry, well-ventilated area; relative humidity ≤80%. Keep away from heat, open flame, direct sunlight, and incompatible materials: combustible organics, reducing agents (sulfites, thiosulfates, metals powders, hydrazine), strong acids (liberates HI/O₃⁻→I₂), and sulfur/phosphorus. This is a Class 5.1 oxidizing solid (UN 1479, PG II); never store with flammables. Handle in a fume hood with nitrile gloves, lab coat, safety goggles; avoid dust generation. Use dry spatula; do not grind with organics. Prepare aqueous solutions fresh if needed; discard if solution turns yellow/brown (iodine liberation). After handling, wash hands thoroughly. Spills: carefully sweep/scoop into dry container, avoid wet mopping (moisture accelerates decomposition); decontaminate with dilute sodium thiosulfate to reduce residual iodate/iodine. Dispose as hazardous oxidizer waste per local regs (WGK Germany 3).

6. Safety Overview

Classified under GHS as Danger: Oxidizing Solid Category 2 (H272: May intensify fire; oxidizer), Skin Irritation Cat 2 (H315), Eye Irritation Cat 2A (H319), Respiratory Irritation (H335). Precautionary: P210 (Keep away from heat/sparks/open flame), P220 (Keep away from combustibles), P221 (Take precautions to avoid mixing with combustibles), P261 (Avoid breathing dust), P264 (Wash after handling), P280 (Wear protective gloves/eyewear), P302+P352 (If on skin: wash with soap/water), P305+P351+P338 (Eye rinse), P501 (Dispose as hazardous waste). Ingestion harmful: may cause nausea, vomiting, abdominal pain (iodate/iodide toxicity; thyroid effects at high dose). Thermal decomposition yields toxic iodine vapors, ammonia, nitrogen oxides—use fume hood for heating. Not for human/veterinary use; lab/analytical only. Transport: UN 1479, Oxidizing Solid, n.o.s. (Ammonium iodate), Class 5.1, PG II. Consult full SDS before use.