What is hypo?

Hypo, also known as sodium thiosulfate and sodium bicarbonate, is a common thiosulfate, colorless and transparent monoclinic crystal. Used as fixative in photography. The melting point of hypo is 48℃ and the boiling point is 100℃.

Sodium thiosulfate is easily soluble in water and reacts with strong acid to generate elemental sulfur and sulfur dioxide gas. Sodium thiosulfate is an antidote to cyanide. It is colorless and transparent crystal or crystal fine particles, odorless and salty, weathered in dry air and deliquesced in humid air. The aqueous solution shows weak alkaline reaction.

With the participation of thiocyanase, it can combine with free cyanide ions in the body or methemoglobin to form nontoxic thiocyanate, which is excreted in urine to solve cyanide poisoning. In addition, it can also combine with a variety of metal ions to form non-toxic sulfide, which is excreted by urine and also has desensitization effect.

The application of Haibo in life is as follows:

Hypo can be used as an antidote to cyanide (such as sodium cyanide) in medicine. In analytical chemistry, sodium thiosulfate is used to titrate the standard solution of iodine. The reaction between them is rapid and complete, and this reaction takes starch solution as indicator.

Haibo is used as dechlorination agent in textile and paper industry. People use chlorine (or chlorine bleach) to bleach fabrics and pulp. The residual trace chlorine will make the fabric or paper fiber yellow or even brittle due to oxidation in the future. In order to remove the residual trace chlorine, we can achieve this goal by using hypo aqueous solution.

Haibo is also used for tanning (reducing metal complex dyes), purifying water in projects and extracting silver from ores.

Hypo aqueous solution can be used for dechlorination and purification of tap water in aquarium of ornamental fish, and the dosage (about 0. 1-0.3 mg/lt based on crystalline hypo).

Some schools have physics teachers who compare the melting points of sea waves and wax for people to observe.