Sodium bromate is an inorganic sodium salt derived from bromic acid, typically presenting as a white, crystalline powder or solid. This compound is recognized as a strong oxidizing agent due to its powerful ability to take electrons from other substances. Its potent chemical reactivity makes it useful across several industrial and laboratory settings, where its controlled release of oxygen facilitates various chemical processes.
Determining the Chemical Formula
The chemical formula for sodium bromate is NaBrO₃. It is an ionic compound formed between the sodium cation (Na⁺) and the bromate anion (BrO₃⁻). The compound consists of one sodium atom (Na), one bromine atom (Br), and three oxygen atoms (O). The structure is determined by the charges of its constituent ions: the sodium cation has a positive charge of plus one, and the bromate anion has a negative charge of minus one. These charges perfectly balance, resulting in a neutral compound.
Key Physical and Chemical Properties
Sodium bromate is a colorless or white crystalline solid that is odorless. It has a high density and exhibits a cubic crystal structure in its solid form. A defining physical characteristic is its high solubility in water, which increases significantly as the temperature rises. The chemical behavior of sodium bromate is dominated by its function as a strong oxidizing agent. When heated to around 381 degrees Celsius, the compound decomposes, releasing oxygen gas and forming sodium bromide.
Common Industrial and Laboratory Applications
The strong oxidizing nature of sodium bromate is leveraged in a variety of industrial processes. One major application is in gold extraction, where it is used as a component of an alternative lixiviant system, often combined with sodium bromide, to dissolve gold from its ores. This method offers an alternative to more common extraction techniques.
In the textile industry, the compound acts as an auxiliary agent for printing and dyeing, assisting in the fixation of sulfur and vat dyes to the fabric. It is also employed in the cosmetic industry, particularly in permanent hair waving solutions. Here, the sodium bromate acts as a neutralizer, oxidizing and reforming the disulfide bonds in the hair’s keratin structure after they have been broken by a reducing agent, which sets the hair into its new shape. Sodium bromate is also a versatile reagent in chemical synthesis, used to facilitate various oxidation reactions, such as converting alcohols to carbonyl compounds.
Safety, Hazards, and Handling
Sodium bromate is classified as a hazardous substance, primarily due to its strong oxidizing properties and its inherent toxicity. As an oxidizer, it can significantly intensify a fire and poses a risk of explosion when it comes into contact with combustible materials, reducing agents, or organic compounds like oil and sawdust. Handling the chemical requires strict separation from all such incompatible substances, and storage must be in cool, dry, and well-ventilated areas.
If ingested, sodium bromate is harmful and can have severe acute effects, including abdominal pain, vomiting, and potential damage to the kidneys. Exposure can also lead to irreversible deafness and affect the nervous system. Personal protective equipment, such as protective gloves and eye protection, are necessary when handling the solid or its solutions to prevent skin and eye irritation.