The principle of NaOH degreasing, the principle of sodium hydroxide degreasing

NaOH degreasing is to replace the atoms of the noble substances in the oxide with the atoms of Na, because Na ranks third in the periodic table of chemical elements and is a relatively active substance, so it can be removed.

The process of degreasing NaOH is called emulsification. It is to emulsify the oil from large particles to small particles. (Whereas the removal of oil stains from gas and oil is a dissolving process).

Other physical and chemical properties When anhydrous copper sulfate is heated to 923K, it decomposes into cuo cuso4==heating==cuo+so3 or 2cuso4==heating==2cuo+2so2 +o2 anhydrous copper sulfate (cuso4) is a white solid, once it absorbs water, it will become blue copper sulfate crystals (cuso4·5h2o), and it can also evaporate the water in copper sulfate crystals to obtain white anhydrous copper sulfate. This change is a chemical change The chemical equation is: CuSO4·5H2O===Heating====CuSO4+5H2O CUSO4+5H2O*****=CUSO4·5H2O Experimental process and phenomenon:

Copper sulfate crystals are placed into a large test tube and heated, and the following can be observed: 1The blue crystals gradually change to white powder of copper sulfate; 2.

Water beads are produced at the mouth of the test tube. In this test, the mouth of the test tube should be slightly downward, mainly to prevent condensate from flowing backwards to the bottom of the test tube, causing the test tube to burst; When heating the test tube, it should be preheated first, and then concentrated heating. This reaction is used to test the water in the product.

Copper sulfate is an inorganic compound, which can be used as a drug when livestock are deficient in copper, and is also used as a tapeworm repellent for cattle and sheep and an emetic drug for pigs and dogs. [This paragraph] preparation method 2Cu + O2 = = 2Cuo Cuo + H2SO4 = CuSO4 + H2O or Cu + 2H2SO4 (concentrated) = Heating = CuSO4 + 2H2O + SO2 or 2Cu + 2H2SO4 + O2 = 2CuSO4 + 2H2O Copper sulfate and iron are replaced to form copper and ferrous sulfate (light green) CuSO4 + Fe = FeSO4 + Cu (wet copper smelting) 2Cu + H2O2 + 4HCl = 2CuCl2+2h2o

It can make the oil saponification reaction to generate the corresponding sodium salt and alcohol of organic acids.

Oils and fats are organic acids, which simply means that the acid-base reaction occurs, and the solubility of the organic salts produced increases.

Sodium hydroxide degreasing is to use its emulsifying effect, which decomposes the oil from large particles to small particles, so that the oil can flow away with the water and remove the oil stain.

Sodium hydroxide. It can cause the oil to undergo saponification reaction, producing fatty acid sodium and glycerol.

Soluble in water, it serves the purpose of removing oil, that is, esters are hydrolyzed in an alkaline environment, and then stearic acid is generated.

and alcohols, stearic acid and alcohols are easily soluble in water, so they achieve the effect of decontamination. However, sodium hydroxide is strongly alkaline and will have a corrosive effect, so protective measures need to be taken.

Sodium hydroxide is widely used, in chemical experiments, in addition to being used as a reagent, because it has strong water absorption and deliquescent, it can also be used as an alkaline desiccant.

Sodium hydroxide in the national economy.

Sodium hydroxide is required in many industrial sectors, with the largest use of sodium hydroxide in the manufacture of chemicals, followed by paper, aluminum, tungsten, rayon, rayon and soap.

Sodium hydroxide is an inorganic compound, which is strongly alkaline and hygroscopic, soluble in water, exothermic when dissolved, and the aqueous solution is alkaline and has a greasy feeling; It is extremely corrosive, and has a corrosive effect on fibers, glass, ceramics, etc., in addition, sodium hydroxide can also be used as a degreasing agent in industry.

Precautions: Staff should take precautions, if accidentally touching ** and eyes, should be immediately rinsed with a large amount of water. The working environment should have good ventilation conditions.

The aqueous solution of sodium hydroxide has a slippery feeling, and produces high heat when dissolved in water.

The principle of soda ash solution for degreasingChemical Equation:

1. The hydrolysis of carbonate ions is alkaline, and the ionic equation of the reaction is：co3

co3+oh-

2. Under alkaline conditions, hydrolysis occurs to generate alcohol and the corresponding sodium carboxylate, and sodium carbonate (Na2CO3) is dissolved. Oil is a long-chain carboxylic acid, generally a mixture, and the oil undergoes saponification reaction with the aqueous solution of alkali at high temperature to produce sodium carboxylate that can be dissolved in water to remove the oil.

Methods of removing grease with alkali:

1. You can use hot water to dissolve the edible alkali. The concentration of edible alkali can be a little higher, and the water temperature can also be a little higher, so that its decontamination capacity will be doubled. Put it in the watering can while it's hot, spray it a few more times where the oil is stained, and in a while we can easily remove the oil.

2. It can be paired with lemon, edible alkali belongs to soda ash, which has strong alkalinity. Lemons contain a large amount of citric acid, which is acidic, and when edible alkali and lemon are added together, they will interact with each other, thus having a strong decontamination ability.

3. It can also be used with salt, edible alkali itself has a certain corrosive cleaning effect, and edible salt has a certain softening and decontamination effect, and the two are used together to have obvious effects on stain cleaning.

Sodium hydroxide can remove grease stains. Because sodium hydroxide can make the oil saponification reaction, generate sodium fatty acid and glycerol and dissolve in water, play the purpose of degreasing, that is, esters are hydrolyzed in an alkaline environment, and then stearic acid and alcohols are generated, stearic acid and alcohols are easily dissolved in water, so the effect of decontamination is achieved.

Sodium hydroxide operation precautionsWhen weighing solid sodium hydroxide, it cannot be weighed directly on a weighing pan or weighing paper, but should be weighed in a small beaker of known quality or on a surface dish, if weighed with a surface dish, the sodium hydroxide solid needs to be transferred to a beaker before dissolving. It should be prepared with carbon dioxide-free water, which should be transferred to a polyethylene bottle immediately after dissolving, and must be plugged with a rubber stopper equipped with an alkali lime tube after cooling. After standing for 24 hours, a certain amount of supernatant is aspirated and diluted with carbon dioxide-free water to determine the volume.

It must be stored in a polyethylene bottle.

The use method of caustic soda degreasing is as follows: sprinkle about 35% of the amount on the oily place, caustic soda is easy to become a lump when it meets water, wet the cleaning tools, and wash directly with caustic soda. The principle of caustic soda degreasing is that esters are hydrolyzed in an alkaline environment to generate stearic acid and alcohols, which are easily dissolved in water to achieve the effect of decontamination.

The method of using caustic soda to remove oil stains is as follows: sprinkle about 35% of the amount on the oily ones. In the place, caustic soda is easy to turn into a lump when it meets water, and after wetting the cleaning tools, it is dipped in caustic soda and washed directly.

The principle of caustic soda degreasing is that esters are hydrolyzed in an alkaline environment to generate stearic acid and alcohols, which are easily dissolved in water to achieve the effect of decontamination.

The chemical composition of the oil is oleic acid with a carboxyl COOH tail. Reaction with alkali NaOH + RCOOH = RCOONA + H O (can be called acid-base neutralization, also called saponification reaction), the product is soap.

Oil + sodium hydroxide--- sodium of high-grade fatty acids + glycerol, the glycerin produced is miscible with water in any ratio, with strong hygroscopicity, and is often used as a skin care agent.

The saponification reaction is limited to the reaction of oil mixed with sodium hydroxide or potassium hydroxide to obtain sodium, potassium salts and glycerol of higher fatty acids. This reaction is a step in the process of making soap, hence the name. Its chemical reaction mechanism was discovered in 1823 by the French scientist Eugène Chevreul.

The chemical composition of the oil is oleic acid with a carboxyl COOH tail. Reaction with alkali NaOH + RCOOH = RCOONA + H O (can be called acid-base neutralization, also called saponification reaction), the product is soap.

The NA end of RCOONA has a very strong electric field force, which is related to the active metallicity of the NA element, which is easy to combine with water (water is a polar solvent). The other end of the fatty acid sodium, like the composition of the oil, can be dissolved with the oil. In this way, the original oil and water are incompatible, but now the sodium fatty acid pulls the oil and water together and becomes an emulsion, and the oil can flow away with the water.

Saponification usually refers to the reaction of bases (usually strong bases) and esters, while alcohols and carboxylates are produced, especially oils and bases.

Oil stains belong to esters, which can be completely hydrolyzed into carboxylates and glycerol under alkaline conditions, and become soluble. But you can't use NAOH to wash aluminum and zinc products. These two metals are amphoteric and can also be dissolved into Naoh.

1.It can react with the grease in the substance, so it can remove the oil and make it alkaline.

The main component of oil staining is grease, which is hydrolyzed under alkaline conditions (preferably heated) to form organic carboxylates and alcohols that are soluble in water.