Sodium carbonate belongs to "strong alkali and weak acid salt", and its chemical properties are alkaline. Often used to neutralize lactic acid in dough.
Natural sodium carbonate, called "soda for returning to the pot", can be eaten and washed. Shampoo can also be used to make soap, which is also used to tan leather.
Sodium carbonate crystals easily lose crystallization water in dry air and become white powder. This powder will "absorb moisture" and become crystals when it is excited in humid air. But the chemical properties remain unchanged.
Sodium bicarbonate, also called baking soda, has the same function as soda. But it is soft and can be used as medicine.
Question 2: What is the use of sodium carbonate? The chemical formula of sodium carbonate (soda ash) is Na2CO3, commonly known as soda ash. It is an important basic chemical raw material and the main product of soda ash industry. Usually white powder, easily decomposed at high temperature, easily soluble in water, and the aqueous solution is alkaline. Soda soda will deliquesce in humid air and slowly absorb carbon dioxide and water, and some of it will become sodium bicarbonate, so the packaging should be strict, otherwise it will absorb moisture and agglomerate, and sodium carbonate and water will generate Na2CO3? 10H2O，Na2CO3？ 7H2O，Na2CO3？ H2O hydrate, including Na2CO3? 10H2O is the most stable, and its heat of solution in water is very small. Mostly used in the photography industry, the trade name is carbon oxygen. Na2CO3？ 10H2O is also called crystalline alkali. Previously, crystalline alkali was often used in household washing and wool washing, so it was also called "alkali washing". In the past, China folk used to use "block soda", which could not only wash clothes, but also mix noodles. It is a mixture of soda ash and a lot of water (in addition, some baking soda (NaHCO3) is added, and its water content is above 50%. Sodium carbonate absorbs heat when it is dissolved in water, and is easily weathered in air. Na2CO3？ 7H2O is unstable and can only be separated from saturated solution of sodium carbonate at 32.5 ~ 36℃. Sodium carbonate is a weak acid and strong base salt. The purity of Na2CO3 prepared by chemical method is higher than that of natural alkali, so people call it "soda ash".
Soda soda is widely used, and its alkalinity is generally used. Can be used to make glass, such as flat glass, bottle glass, optical glass and high-grade utensils; Soap can also be made by reacting fatty acids with soda ash; It is used to soften hard water, refine petroleum and oil, remove sulfur and phosphorus in metallurgical industry, process minerals, prepare metals such as copper, lead, nickel, tin, uranium and aluminum, prepare sodium salts, metal carbonates, bleaches, fillers, detergents, catalysts and dyes in chemical industry, and soda ash is also used to manufacture refractories and glazes in ceramic industry.
Soda soda ash is an important large-tonnage chemical raw material. Soda production includes Suwei method, Hou Shi soda production method and natural alkali processing method. Different processing methods have different raw materials. The main raw materials are crude salt (including sea salt, pond salt, mineral salt and underground brine), trona, limestone and ammonia. The main alkali plants in China are Dalian Chemical Company, Tianjin Alkali Plant, Qingdao Alkali Plant, Zigong Honghe Chemical General Factory and Hubei Chemical Plant.
Question 3: the use and usage of edible soda ash. What is edible alkali? What are the functions of eating alkali that you don't know? Alkali is not a common condiment, but a kind of food swelling agent and meat tenderizer, which can make dry raw materials swell rapidly, soften fibers and remove the sour taste of dough. Proper use can bring excellent color, fragrance, taste and shape to food, thus increasing people's appetite.
Although edible alkali is not a common condiment, it can do many things if you can use it skillfully. Let's look at the function of edible alkali.
The function of edible alkali
1. Blanch hairtail in hot alkaline water at about 80℃ 10 second, immediately take it out and put it in cold water, then brush it with a brush or touch it with your hands to quickly remove its powder scales.
2. Choose corn flour or corn porridge and put some alkali in the right amount. Corn contains a kind of combined nicotinic acid, which is not easily absorbed by human body. Long-term consumption of corn food will lead to niacin deficiency and easy to get boils. Alkali can convert bound nicotinic acid into free nicotinic acid, which is beneficial to human absorption.
3. Edible alkali can shorten the time of stewing meat, boiling beans and cooking, and make dishes easy to mature and soft. However, alkali will destroy B vitamins, vitamin C, vitamin D and other nutrients, affecting the absorption of nutrients by the human body.
4. As the saying goes, salt is bone alkali and tendon. "Adding a proper amount of salt and edible alkali to the dough can enhance the strength of the dough, improve the physical properties of gluten, make the texture more dense, and enhance the elasticity and strength. So that the dough is not easy to break when stretched or expanded. After the dough is tightly organized, the color of the finished product will appear white.
5, white towel used for a long time, will turn yellow and hard, very uncomfortable to use. You can put the towel in a pot or basin, add some water, sprinkle a handful of alkaline noodles and cook for a few minutes. When the water is not hot, rub the towel a few times and rinse it with hot water. In this way, the yellow stain on the towel can be basically eliminated, which is much softer.
6. The old mildew spots on the fabric can be removed by scrubbing with weak alkaline water.
7. The smoke stains on the fabric can be scrubbed with glycerin at 50℃ and then scrubbed with alkaline water.
8. Gypsum stains on the fabric can be removed by rubbing with alkali powder and a little warm water for several times.
Question 4: What is the use of sodium carbonate? 20 points in industry, mainly light industry, building materials and chemical industry, accounting for about 2/3; Followed by metallurgy, textile, petroleum, warehousing, national defense, medicine and other industries. It is also used to produce synthetic detergent additives, such as sodium tripolyphosphate and other sodium phosphate salts. Edible soda ash is used to produce monosodium glutamate, pasta and so on.
Question 5: Is sodium carbonate edible? It's soda, you can definitely eat it, but if you have stomach trouble, you'd better not eat it, because it's gastric mucosa.
Question 6: Excuse me, what is the implementation standard of edible soda ash? Review the emergency use guide of "material quantity"
Firstly, the relationship between the quantity, mole and Avon Garderot constant is clarified.
The quantity of matter is one of the seven most basic physical quantities in the International System of Units (SI), which is used to represent the quantity of microscopic particles (or a specific combination of these particles). When we measure the quantity of matter, we usually use the mass, volume and quantity of matter. Mole (mol) is the SI unit of the amount of matter; Avogadro constant NA is the measurement standard of mol, which is equal to the number of carbon atoms in 0.0 12Kg 12C. According to the definition, the Avo Gadro constant itself is an experimental value, and its latest experimental data Na = 6.0220943×1023mol-65433. If the number of oxygen molecules is twice this number, it can be recorded as 2molO2.
Second, remember the preparation of the concentration solution of the two substances.
1. Preparing solutions from solids
Steps: ① calculation, ② weighing, ③ dissolution, ④ transfer, ⑤ washing, ⑤ constant volume and shaking.
Instruments: volumetric flask, tray balance, beaker, glass rod, rubber dropper.
2. Prepare dilute solution from concentrated solution
Steps: ① Calculation, ② Measurement, ③ Dilution, ④ Transfer, ⑤ Washing, ⑤ Constant volume shaking.
Instruments: volumetric flask, measuring cylinder, beaker, glass rod, rubber dropper.
Third, understand three formulas.
1. General formula for calculating the amount of substance: n = m/m = v (g)/vm = n/na = c * v = xs/[m * (100+s)].
Where n is the amount of substance in moles; ; M is the material quality, in grams; M is the molar mass in g? mol- 1； V(g) is the volume of gas in liters; Vm is the molar volume of gas in l? mol- 1； N is the number of particles, and NA is Avon Gadereau constant 6.02×1023mol-1; C is the concentration of the substance, in moles? l- 1； V(aq) is the volume of the solution in liters; X is the mass of saturated solution in grams; S is the solubility in g.
When answering the question of Avon Garderot constant (NA), we must pay attention to the following subtle knowledge points:
① Non-gaseous substances: water, bromine, SO3, carbon tetrachloride, benzene, octane, chloroform and so on. It can't be converted into substance by VM = 22.4 L/mol.
② Number of atoms in a molecule: oxygen, nitrogen and fluorine are diatomic molecules, while rare gases (monatomic molecules), white phosphorus (P4) and ozone (O3).
③ The number of electrons transferred in complex redox reactions: Na2O2 and H2O, Cl2 and NaOH, KClO3 and hydrochloric acid, copper and sulfur, electrolytic AgNO3, etc.
2. Dilution of a certain mass fraction solution
ω 1? m 1=ω2？ M2 (mass conservation of solute before and after dilution)
ω 1 is the mass fraction of the solution before dilution, and m 1 is the mass of the solution before dilution; ω2 is the mass fraction of the diluted solution, and m2 is the mass of the diluted solution.
3. Dilute the solution with a certain amount and concentration of substances.
C 1 is the concentration of substances in the concentrated solution before dilution, and c2 is the concentration of substances in the diluent; V 1 is the volume of the solution before dilution, and V2 is the volume of the solution after dilution.
Fourth, master the four inferences of Avon Gardlow's Law.
Avon Gadereau's Law (Four Laws): Any gas with the same temperature, pressure and volume contains the same number of molecules or the same amount of gas substances. The molar volume of gas is a special case of Evan Garderot's law.
1. Inference 1: At the same temperature and pressure, the volume ratio of gas is equal to the volume ratio of substances and the volume ratio of molecules (v1:v2 = n1:n2 = n1:n2).
2. Inference 2: At the same temperature and pressure, the density ratio of gas is equal to the ratio of its relative molecular mass (ρ 1:ρ2=M 1:M2).
3. Inference 3: At the same temperature and pressure, the volume ratio of gas with the same mass is inversely proportional to the relative molecular mass (V 1:V2=M2:M 1).
4. Inference 4: At the same temperature and volume, the pressure ratio of gas is equal to the quantity ratio of substances (P 1:P2=n 1:n2).
The above Avon Gadereau law and inference must be memorized and understood, and must be deduced by the ideal gas state equation (PV=nRT=m/M *RT).
Verb (abbreviation of verb) distinguishes five concepts.
1.mole: If a certain amount of particles contain the same number of particles as 0.0 12Kg 12C, then ... >; & gt