Bromine water: its properties and features
Bromine is a substance that, like mercury, is in a liquid state at room temperature. It is very toxic, but is widely used in the chemical industry and laboratories. Refers to the halogen group, but weaker than chlorine. When passing through water, forms a solution called bromine water.
Bromine and bromine water preparation
The element itself is a reddish-brown liquid with a strong, unpleasant odor. You should not breathe it, because you can get poisoned, and this desire is unlikely for anyone. The name itself speaks about this property, because bromine in translation from ancient Greek means “stinker”, “stinky”.
The molecule is diatomic, and its formula is Br2. The element itself was found in 1826 and brought fame to its discoverer - the young teacher Antoine Balar. Bromine is widespread everywhere, but most of all it is found in seawater and salt lakes. Used in manufacturing and laboratories is not the substance itself, but its solution, which is easy to prepare.
Prepare a solution of bromine water only in a fume hood due to the toxicity of the vapor. To do this, take bromine in a volume of one milliliter and pour it into water (distilled, otherwise you will get a lot of unnecessary impurities) with a volume of 250 milliliters, intensively stirring with a glass rod. Bromine water is ready.Keep it only in a dark glass, tightly closed. Be careful, as contacting with the skin, bromine causes severe and painful burns. If contact occurs, rinse the affected area immediately with water.
Composition of bromine water
Not only bromine molecules (Br2), but also bromine acids HBrO and HBr. It is the presence of the first (hypobromous acid) that makes the solution stored in a dark glass, as it decomposes in the light, releasing oxygen.
Chemical and physical properties
In appearance, bromine water is an orange-yellow liquid that takes its unpleasant odor from the main substance. The temperature at which the solution freezes is rather low. Even at -20 ° C it is liquid.
Like all halogen solutions, bromine water is an excellent oxidizing agent, but weaker than chlorine solution. It oxidizes metals and many organic compounds, including phenols. And adding more bromine to it leads to a decrease in pH.
Bromine water is used in industrial laboratories. One of the qualitative reactions to unsaturated hydrocarbons is precisely the interaction of alkenes and alkynes with a solution of bromine water. As a result, the composition is discolored. Breaking double and triple bonds, bromine joins, forming bromide compounds.
Bromine water also becomes discolored by reacting with unsaturated oils. They also have double and triple bonds. The interaction with bromine water of potassium iodide leads to discoloration of the first and gradual release of free iodine molecules (I2). It is possible to carry out a qualitative reaction with the presence of CuCl with bromine water, with the addition of a small amount of ammonia solution, reddening will occur.
In medicine, bromine water is used in the manufacture of drugs. There used to be a legend that soldiers are given bromine as food to lower their potency. But there are no grounds for this statement, since the substances containing bromine do not have any effect on the male power. They simply act on the nervous system as a sedative and mild sleeping pill.
But using medicinal substances containing bromine, you should be very careful, as long-term use can cause such a disease as bromism. The main symptoms of the disease - a general breakdown, accompanied by a rash on the skin and lack of appetite. To normalize the condition, an active substance must be urgently removed from the body. To do this, prescribe a large amount of liquid and food with a high content of salts.
Bromine water is also used in construction - at different stages of production of substances that protect fabrics, wood, building materials from flame. These substances are also called flame retardants.Bromine water and bromides are used in flights, for rocket fuel oxidation, in oil production, in agriculture (production of pesticides and insecticides).