The Reaction Between Bromine Water

Bromine is the third lightest of the halogen elements, emitting red-brown vapours at room temperature and is evaporated to produce a similar-coloured gas. Bromine, in its elemental state, is very reactive. It does not exist naturally. Carl Jacob in 1825 and Antoine Ballard in 1826 were the first two scientists to identify bromine. Bromine is substantially less common in the crust than fluorine or chlorine. It is the 46th most abundant component in the earth’s crust. Due to a significant long-term extraction stage, bromine is now more commonly found in oceans.

Bromine water testing determines the presence of alkene or alkane hydroxyl groups in a chemical. It causes an additional reaction, resulting in a decolourised solution.

Manufacture of Bromine

A supply of chloride and a solution containing bromide ions is required to make bromine in the lab. Bromine should be adequately isolated from the solution after its creation.

The following is how oxidising bromide ions make bromine:

2Br-(aq) → Br₂(l)+2e-

There are two steps to the procedure:

1. Oxidation of bromide ions to bromine.
2. Purification of bromine.

Oxidation of Bromide Ions to Bromine

Chlorine and water are pushed up by blowing the tower and down the heated brine that contains many bromide ions.

Bromine can be extracted from such a solution by oxidising bromide ions with chlorine gas:

Cl₂(g) + 2Br-(aq) -> 2Cl-(aq) + Br₂(g).

The reaction between bromine water and different functional groups are mentioned below:

1. Alkene

An additional reaction happens between bromine and alkene. For instance, when ethene combines with bromine water, it forms 1, 2 dibromo ethanes. If the reactants are gaseous, the reaction must happen at room temperature (ethene). Even as bromine water solution combines with ethene, it loses its colour.

However, mainly in the existence of tetrachloromethane, fluid alkenes such as cyclohexene interact in bromine water solution.

2. Aniline

Bromine water interacts with aniline or phenylamine. This reaction forms a white precipitate and the decolourisation of brome water.

3. Enol

The brominated ketone is generated when enols are subjected to something like a bromine water test.

4. Ketones

The electrophilic alpha replacement reaction happens between the ketone and bromine water close towards the carbonyl group, yielding a clear solution of brominated molecules.

5. Aldehydes

When aldehyde combines in bromine water, an oxidation process occurs, resulting in colourlessness.

6. Glucose

Bromine water testing is an effective and easy way to tell between fructose and glucose. When glucose reacts to bromine water, it conducts an oxidation process, yielding glucuronic acid. Fructose does not initiate an oxidation process because bromine water is a moderate oxidising agent.

7. Phenols

In addition to bromine water, phenols undertake electrophilic substitution, yielding a brominated product. Bromine water is decolourised throughout the procedure, resulting in some white residue.

8. Alkane

The alkane compound does not interact with the bromine liquid solution. Hence, the bromine solution retains its deep yellow colour.

Process for Detachment of Bromine

Bromine, chloride, and water vapour combine to generate a hot exhaust combination blasting from a building’s top. This combination goes via a few phases, as below.

1. The process of condensation

As the title suggests, the gas mixture gets cooled down throughout this stage. Bromine may evaporate just when the hot exhaust combination enters the condenser. Because the temperature in the extractor is insufficient for the chlorine gas to concentrate, it gets separated from the water. Chlorine exists in bromine, and the water-rich evaporator goes towards the reaction tower as it separates. The chlorine-containing liquid solution and the water and bromine-containing liquid phase are separated in a splitter.

2. Distancing

Two layers develop inside the divider: the heavier upper and the lower bromine layers. Its liquid is the lightest and uppermost layer. Bromine and chlorine, mildly water-soluble, are present inside the water layer. The layers get returned towards the reaction tower once the separation is complete. The bromine layer, which contains chlorine and water as contaminants, is filtered further.

3. Drying and filtration

Bromine is not entirely pure after the separation process, as it contains chlorine & water. Bromine was extracted from chlorine, but most of the water was distilled. Also, the chlorine and most of the water recirculated into the response tower. A drying method, such as treating moist bromide using strong sulphuric acid, eliminates the remaining water.

Bromine can also be produced in a factory setting.

Conclusion

Bromine is highly soluble in water and is a natural element. It dissolves in water and has a reddish-brown hue with a bleach-like odour.

Bromine is commonly made by injecting chlorine into bromide-rich, pH-3.5 aqueous mixtures. Hydrogen chloride and air are used to clean saltwater. Bromide is oxidised to bromine by chlorine. The bromine water testing assesses if hydrocarbons are saturated or unsaturated. Bromine water tests are easy to perform on organic substances, including phenols, alkenes, acetyl compounds, and anilines. The existence of an unsaturated group inside the organic molecule is indicated by a change in the colour of the bromine water during the procedure.