Sodium sulfite is perishable in the air, what is sodium sulfite deterioration

Sodium sulfite is easy to deteriorate in the air, take a little sodium sulfite sample in the test tube, add distilled water to prepare a solution, add a sufficient amount of hydrochloric acid and barium chloride solution, if there is a large number of bubbles without precipitation phenomenon, then there is no deterioration, the ion equation is 2H+ +SO32- = SO2 +H2O, if there are bubbles and a small amount of white precipitation phenomenon, then part of the deterioration, if there are no bubbles and a large amount of white precipitation phenomenon, then complete deterioration.

If only bubbles are generated, they are not deteriorated, 2H++(SO3)2-=H2O+SO2; If there are both bubbles and precipitation, it is partially metamorphosed, 2H++(SO3)2-=H2O+SO2,BA2++ SO4)2-=BASO4; If only the precipitate is produced, it will all deteriorate, Ba2++(SO4)2-=BaSO4

If only bubbles are generated, there is no deterioration, 2H++(SO3)2-=H2O+SO2; If there are both bubbles and precipitation, it is partially metamorphosed, 2H++(SO3)2-=H2O+SO2,BA2++ SO4)2-=BASO4; If only the precipitation is produced, all will deteriorate, Ba2++(SO4)2-=BaSO4

Sodium sulfiteAfter deterioration, it is sodium sulfate. Sodium sulfite dew deteriorates when placed in the air because the sodium sulfite is oxidized by oxygen in the air to form sodium sulfate.

Chemical reaction. The equation is: 2Na2SO3 + O2 = 2Na2SO4. Sodium sulfite is easily oxidized by oxygen in the air, and a little sodium sulfite is often added to water as an oxygen scavenger.

Prevent the oxidation of oxygen in the water by other auspicious substances.

The method of sodium sulfite storage is as follows.

Due to the unstable nature of sodium sulfite, it should be stored in a dry place below 3 0.

Sodium sulfite is a strong reducing agent.

It is easy to be oxidized under the action of humid air and sunlight, and it will decompose when heated, so it is necessary to keep the product away from the fire source and the hot sail source, and the storage area should be equipped with suitable materials to contain the leakage. When storing, it should be stored separately from acids, etc., and should not be mixed. And sodium sulfite is not suitable for long-term storage, so it is recommended to purchase it according to the production demand.

It should be stored in a cool, dry warehouse Hengyan. The packaging of the product must be sealed and not in contact with the air to prevent moisture and deterioration.

Sodium sulfide solids deteriorate when exposed to air. This is because the sulfur ions in sodium sulfide are strongly reducible. It can be oxidized by oxygen in the air to elemental sulfur.

If the precipitate is completely insoluble and no bubbles are generated, it means that it has completely deteriorated.

To test whether a sodium sulfite powder has not deteriorated, whether it is partially deteriorated or completely deteriorated, the same two reagents can be used, BaCl2 solution and dilute hydrochloric acid. It should be emphasized that nitric acid cannot be used to replace hydrochloric acid, nor can BA(NO3)2 be used instead of BACl2 (adding barium nitrate to Jianling Town in excess of hydrochloric acid will also produce nitric acid), because Na2SO3 or BaSO3 will be oxidized by Hno3, which affects the judgment.

The use of sodium sulfite is contraindicated.

Sodium sulfite is a reducing bleach, and its solution is unstable and volatile, so it is now prepared and used to prevent sulfite from being unstable and volatilizing.

In the presence of metal ions in food, the residual sulfurous acid can be oxidized, and the reduced pigment can also be oxidized and discolored, thereby reducing the effectiveness of the bleach. Therefore, metal chelating agents are used at the same time in production.

The coarse substance bleached with sulfites is easy to recolor due to the disappearance of sulfur dioxide, so excess sulfur dioxide is usually left in food, but the residue should not exceed the standard.

The above content refers to Encyclopedia - Sodium Sulfite.

Summary. Hello, I am glad to answer for you that sodium persulfate reacts with air because sodium persulfate is more stable, but because of its high melting point, it will decompose in direct contact with air at room temperature.

Sodium persulfate reacts with air.

Hello, I am glad to answer for you that the reaction between sodium persulfate and air is perthiomegalone, which is more stable, but because of its high melting point, it will decompose in direct contact with air at room temperature.

The sodium persulfate solution is an acid reaction, which can be decomposed by alcohol and silver ions, and can also be burned with the combustible matter or easily oxidized Lingpei material, and can support combustion and fuel the fire. It will slowly decompose when stored.

Equation. Hydrophilic formula: Na2S2O8

Main reaction: (NH4)2S2O8+2NaohNa2S2O8+2NH3 +2H2O

Sodium sulfite is a common chemical reagent that is widely used in industry, food processing, beverage production and other fields. In order to ensure its quality, we need to use some methods to test whether the sodium sulfite has deteriorated.

A simple way to test if sodium sulfite has deteriorated is to use direct observation. First of all, you need to check the appearance of sodium sulfite, fresh sodium sulfite should be colorless, odorless and tasteless, and exist in the form of crystals. If the sodium sulfite is yellow or even brown in color, or has an odor, it may have deteriorated and can no longer be used.

Another way to test if sodium sulfite has deteriorated is to use the acid-base indicator method. This method requires some chemical indicators such as phenol red or methyl orange. First, dissolve a small amount of sodium sulfite in water and add a few drops of acid-base indicator.

If the color of the indicator changes to red, it means that the sodium sulfite contains free acids and may have deteriorated. Whereas, a fresh sodium sulfite solution should be colorless.

In addition, the redox method is also an effective way to test whether sodium sulfite has deteriorated. This method requires some chemical reagents, such as potassium permanganate solution or iodine solution. Sodium sulfite solution is mixed with potassium permanganate or iodine solution, and if an oxidation reaction occurs, it means that the sodium sulfite has deteriorated.

Of course, in order to more accurately test whether sodium sulfite is deteriorating, we also need to carry out a series of quantitative analysis experiments, such as gravimetric method, titration method, etc. These methods require more specialized instrumentation and experimental conditions, and are generally performed in the laboratory.

In general, the deterioration of sodium sulfite can be preliminarily detected by direct observation, acid-base indicator method and redox method. If you need to detect grip defects more accurately, you need to use some advanced chemical analysis methods. <>

No special conditions are required.

1. Sodium sulfite has obvious reducing property and is easy to be oxidized when encountering oxidants.

2. Oxygen in the air can oxidize sodium sulfite

2na2so3+o2=na2so4

3. Some other unknown oxidants in the air may also oxidize sulfurous acid.

If I have to say condition, it is to be exposed in the air.

The rate of oxidation is not too fast.

Sulfur dioxide is oxidized by oxygen in the air when it comes into contact with catalytic substances such as dust.