Alkali corrosion, apply a lot of what to rinse, what to use and what to clean, and finally rinse wit

Soak in light salt water. Rinse the dirt on the surface of the body first, then soak it in light salt water for a period of time, soak it in light salt water to let it spit out the dirt in the stomach.

Scrub the crabs. When the water spit out by the crab is no longer cloudy, clean the crab with a brush, which requires a certain amount of skill to prevent the crab's claws from getting caught in the fingers. Pinch the left and right sides of the crab firmly with your thumb and middle finger and place the shell upward.

After grasping the crab, take it under the faucet, turn on a thin stream of water, brush the crab with a toothbrush, and rinse it while brushing. When brushing, you should brush hard, especially the crab hair, because the crab hair is the dirtiest.

After brushing the thighs, brush both sides of the crab cover and two crab claws with a toothbrush, especially the crab claws must be brushed a few more times, because the crab claws are hairy and easy to hide dirt and dirt.

Clean the abdominal cover. There is a lot of dirt and crab excrement in the belly cover. Open the belly cover, squeeze out the excrement in it first, then scrub off the dirt in the belly cover, and finally scrub the crab claws clean.

The cleaned crabs are thrown into a basin of clean water, and finally rinsed together and can be used for cooking.

Drunken crab with white wine. After putting the crab in the basin, pour an appropriate amount of water, and then pour in a small amount of liquor and mix well, so that the crab will get drunk and become comatose after drinking the water containing liquor, and you will have no strength to pinch people at your mercy.

Rinse with plenty of water, rinse with boric acid, and rinse with water.

The alkali used in cleaning containers using the alkali method is: sodium carbonate.

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1. Sodium carbonate is an inorganic compound with the molecular formula of NaCO and molecular weight, also known as soda ash, but it is classified as salt and not alkali. Also known as soda or soda ash in international **. It hail powder is an important inorganic chemical raw material, mainly used in the production of flat glass, glass products and ceramic glaze.

It is also widely used in household washing, acid neutralization, and food processing.

2. Sodium hydroxide.

sodium hydroxide), also known as caustic soda.

Caustic soda, caustic soda cultivation.

It is an inorganic compound, the chemical formula NaOH, sodium hydroxide has strong alkaline, very corrosive, can be used as acid neutralizing agent, masking agent, precipitant, precipitation masking agent, chromogenic agent, saponifying agent, peeling agent, detergent, etc., with a wide range of uses.

a Hydrolysis of oil under alkaline conditions, soda ash hydrolysis is alkaline, heating promotes hydrolysis, and the alkalinity of the solution is enhanced, which can promote the hydrolysis of oil, so a is correct;

b Electrolysis of sodium hydroxide solution, which is essentially electrolysis of water, and the pH of the solution increases, so B is wrong;

c In aluminum-air batteries, aluminum is the negative electrode, oxidation reaction occurs and is oxidized, air is the positive electrode, oxygen gets electrons and is reduced, so c is wrong;

d The reaction between the positive electrode of the galvanic cell and the cathode of the electrolytic cell is a reduction reaction, so D is wrong so A is chosen

A Analysis: The item should be wiped with a rag first, and then washed with a large amount of water; It is not possible to prepare the solution in a graduated cylinder.

(1) Sodium hydroxide. Sodium hydroxide is a strong alkali, has good saponification ability, and the chemical reaction with stearic acid in animal and vegetable oil is (C17H35COO)3C3H5+3NaOH - 3C17H35Coona+C3H5(OH)3 Sodium Stearate Sodium Hydroxide Soap Glycerin The original insoluble oil becomes soluble in water (especially hot water) soap and glycerin and is removed, but the wetting and emulsification effect is poor, and it has a corrosive effect on non-ferrous metals, especially aluminum. For this reason, the concentration of sodium hydroxide in the alkali etching solution is low, and sodium hydroxide is often not used in the chemical cleaning solution.

2) Sodium carbonate. Although the solution of sodium carbonate is alkaline, it has no obvious corrosive effect on aluminum parts within the allowable range, and can be converted into sodium hydrochloride after absorbing carbon dioxide in the air, which has a good buffering effect on the pH value of alkali etching solution and chemical cleaning solution. Sodium carbonate solution has a good degreasing effect.

3) Trisodium phosphate. Trisodium phosphate has the same advantages as sodium carbonate, the degreasing effect and buffering effect are better, in addition to a certain emulsifying effect, because of its good water washability, it is helpful for the elution of sodium silicate. (4) Sodium pyrophosphate.

In addition to the similar characteristics of sodium pyrophosphate, sodium pyrophosphate also has the ability to complex, preventing the formation of insoluble hard water soap film on the surface of the workpiece, so as to improve the cleaning quality after chemical cleaning. (5) Sodium metasilicate. Sodium metasilicate is an ingredient in the process formula of chemical cleaning or alkali etching of aluminum parts, some can be replaced by sodium metasilicate, whether sodium metasilicate or sodium silicate has good surface activity and a certain saponification ability, and has a slow filling effect on aluminum, when it is combined with other surfactants, it becomes the best wetting agent, emulsifier and dispersant in alkali compounds.

When sodium silicate is used or sodium metasilicate alone, the washing performance is relatively poor, and the residue becomes insoluble silica gel when it meets the acid, so it should be taken more seriously when cleaning in clean water containing sodium silicate or alkali etching. (6) Emulsifiers. The emulsifier has a good emulsification and activation effect, and can play a role in accelerating the degreasing process in chemical cleaning or alkali corrosion, and is beneficial to the removal of mineral oil, which can reduce the surface tension of the interface between the oil and the solution, and at the same time, under the action of convection and stirring of the solution, the grease can be separated from the surface of the workpiece, and dispersed in the solution in the state of tiny oil beads, and the molecules of the surfactant are surrounded by the surface of the small oil beads, so as to prevent the possibility of small oil beads re-adhering to the workpiece.

In the use of 0p emulsifier and Pingjia series emulsifier, it is mostly used.