Chemical Identity and Physical Properties

Zinc acetate dihydrate (Zn(CH3COO)₂·2H₂O, CAS 5970-45-6) is the dihydrated form of zinc acetate, a white crystalline solid with a faint acetic acid odour. Its molecular weight is 219.50 g/mol. The compound is freely soluble in water and sparingly soluble in ethanol. Aqueous solutions are mildly acidic due to partial hydrolysis of the zinc cation, typically yielding a pH of approximately 5–6 at a 5% (w/v) concentration.

The crystal structure features zinc centres coordinated by acetate ligands and water molecules, giving rise to a layered arrangement in the solid state. Upon heating above ~100 °C, the compound progressively loses its two water molecules of crystallisation; further heating leads to decomposition rather than a clean melt. The anhydrous form (CAS 557-34-6) is distinct and should not be confused with the dihydrate when preparing solutions of defined molarity.

Key Laboratory Applications

Nanoparticle and Thin-Film Synthesis: Zinc acetate dihydrate is one of the most widely used precursors for the synthesis of zinc oxide (ZnO) nanoparticles and nanostructured thin films. Both sol-gel and hydrothermal routes commonly employ it as the zinc source, yielding ZnO materials relevant to photocatalysis, UV-blocking coatings, and semiconductor research.

Coordination and Supramolecular Chemistry: As a labile zinc(II) salt with a weakly coordinating counterion, it serves as an entry-point reagent for assembling metal–organic frameworks (MOFs), coordination polymers, and model complexes probing zinc metalloenzyme active sites.

Biochemical and Cell Biology Assays: Zinc acetate is used to precipitate nucleic acids and proteins, to supplement cell culture media with zinc ions at defined concentrations, and as a fixative component in some histological protocols. It is also employed in enzyme activity studies involving zinc-dependent enzymes such as carbonic anhydrase and alcohol dehydrogenase.

Analytical Chemistry: The compound serves as a standard zinc source for atomic absorption spectroscopy (AAS) calibration solutions and as a reagent in gravimetric and volumetric methods for the determination of sulfide, phosphate, and other anions.

Electrochemistry: Zinc acetate dihydrate is used in electroplating baths, in the preparation of zinc-containing electrolytes for battery research, and in electrodeposition of ZnO films.

Handling, Storage, and Safety Considerations

Personal Protective Equipment: Standard laboratory PPE is recommended when handling zinc acetate dihydrate: nitrile gloves, safety glasses, and a lab coat. In operations generating dust, a half-face respirator with a P2/N95 particulate filter should be used.

Storage: Store in a tightly sealed container in a cool, dry, well-ventilated area away from strong acids, strong bases, and oxidising agents. The compound is hygroscopic and should be re-sealed promptly after use to prevent uptake of atmospheric moisture, which could alter its effective purity and alter solution concentrations if weighed after prolonged exposure.

Stability: The dihydrate is stable under normal laboratory conditions. Avoid prolonged heating, which drives off water of crystallisation and converts the salt toward the anhydrous form or promotes decomposition to zinc oxide and acetic acid vapour.

Waste Disposal: Zinc-containing waste must not be poured down the drain in quantities that exceed local regulatory limits. Collect zinc-containing solutions in labelled waste containers and dispose of according to institutional and local regulations for heavy-metal-containing waste.

GHS Classification: Zinc acetate dihydrate is harmful if swallowed and is classified as an aquatic toxicant. Refer to the Aladdin Scientific Safety Data Sheet (SDS) for complete hazard information before use.

Purity, Grades, and Quality Considerations

For most research applications, a reagent-grade or ACS-grade zinc acetate dihydrate with a purity ≥98–99% is appropriate. Critical applications such as preparation of ICP-MS or AAS calibration standards may require a certified reference material or a Traceable standard with a stated uncertainty.

Aladdin Scientific's Z433040 is produced under GMP-compliant conditions at its Fengxian Phase II facility and corresponds to a Sigma quality benchmark (internal reference 1.088). Researchers should consult the certificate of analysis (CoA) accompanying each lot for the actual assay value, heavy-metal impurity levels, and other specification parameters before use in sensitive assays.

When preparing stock solutions, note that the molecular weight of the dihydrate (219.50 g/mol) must be used rather than that of the anhydrous salt (183.47 g/mol) to achieve the correct molar concentration. A 1 M stock solution requires dissolving 219.50 g in water and making up to 1 litre; always verify the final pH and adjust if necessary for biologically sensitive experiments.

Ordering and Availability at Aladdin Scientific

Zinc acetate dihydrate is available from Aladdin Scientific under SKU Z433040. The product is manufactured at the Fengxian Phase II GMP production facility, ensuring consistent batch-to-batch quality with full traceability documentation.

To place an order, visit the Aladdin Scientific website, search for SKU Z433040, select the required pack size and quantity, and proceed through the standard checkout process. Volume pricing and institutional account options may be available; contact your Aladdin Scientific account manager or the customer service team for quotations on bulk quantities or standing orders.

A Safety Data Sheet (SDS) and Certificate of Analysis (CoA) for each lot can be downloaded from the product page or requested from the technical support team. For questions regarding specification, regulatory documentation, or custom pack sizes, please contact Aladdin Scientific customer support.