Sodium Acetate

About This Product

Sodium acetate, C2H3NaO2, is supplied anhydrous with CAS number 127-09-3 or as the trihydrate, in white crystals or granules, freely soluble in water and giving a mildly alkaline solution. The trihydrate shows an unusually clean example of supersaturation. Heated until it dissolves in its own water of crystallisation and then cooled undisturbed, it remains liquid well below the temperature at which it should have solidified, because there is no nucleation site for crystals to start from. Flexing a small metal disc in the pack provides that site, and crystallisation propagates through the whole mass in seconds, releasing the latent heat of fusion as a sudden warmth of around 54 degrees Celsius. Boiling the pack redissolves the crystals and resets it, indefinitely. Its industrial uses are more prosaic: it buffers dye baths in textile processing, where pH drift changes shade; it neutralises sulphuric acid waste streams; it is used in the sodium acetate step of photographic and leather processing; and as a concrete sealant it reduces water ingress and freeze-thaw damage. It is used in reusable heat packs, textile dyeing buffers, effluent neutralisation, concrete sealing, leather tanning and electroplating. Bio Green Chem supplies sodium acetate to specification on assay, pH, loss on drying, chloride, sulfate, iron and heavy metals.