Film: 3846

Science | 1950 | Sound | B/W


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Chemistry. Bromine production. Good shots of chemical apparatus, distilling and test tube experiments, bubbling and boiling liquids in glass tubes and bottles.

Bromine experiments, mixing it with phosphorus. Mixing bromine with hydrogen creates Hydrobromide. Mixing with aluminium causes reaction so that aluminium burns. Aluminium Bromide added to water causes reaction. phosphorus and bromide added to water causes water to boil, intense heat generated.
Hydrogen Bromide is soluble in water.
Bromine in water settles to the bottom of the container therefore it is more dense than water. It is not soluble on its own. Bromine can exist in various solutions.
Experiments to extract bromine from sea water to produce the element bromide.
Seawater is concentrated by 50 times. The sea water changes colour due to the increase concentration of bromine. Bromine ions need to be oxidized to produce elemental bromide. Experiment using oxygen to oxidize bromine in sea water. The reaction is too slow. Experiment using chlorine to oxidize bromine in sea water. The reaction is greater than when using oxygen and the sea water changes colour.
Experiment using concentrated sea water. Acid is added, then chlorine is added and elemental bromide is produced. How to separate the bromide from the solution? Compressed air extracts the bromide but how to collect it.
Experiment adding sulphur dioxide to bromine produces vapour which is Hydrogen Bromide, the solution is distilled to extract the bromide.
Narrator says £100 million of bromine is extracted from sea water every year. Look at an industrial plant which uses the same processes as the experiments in the laboratory. Concentrated sea water and acid and chlorine, uses air to blow bromine out of the solution to give a vapour then sulphur dioxide to produce Hydrogen Bromide then chlorine again to give bromide which is then concentrated.

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