Why does aluminum corrode in salt water?

Aluminum is a reactive metal that is aluminium in dry air.

A dense oxide film with a thickness of about 50 angstroms (1 angstroms = nanometers) is immediately formed on the surface, so that the aluminum will not be further oxidized and can resist water; However, the powder of aluminum is extremely flammable when mixed with air; Molten aluminium can correspond violently to water as a metal; Aluminum is amphoteric and highly soluble in strong alkalis and can also be soluble in dilute acids.

Cl adsorption replaces oxygen on the surface of the oxide film.

Alcl3 is formed, which is easily soluble in water), forming pores. Due to the trace amount of iron, silicon, copper and other impurities in aluminum, when aluminum products come into contact with electrolyte solutions (NaCl solution, etc.), aluminum will be corroded due to the action of galvanic cells. In addition, the amount of MgCl2 (MgCl2 hydrolysis is slightly acidic) in table salt often causes the galvanic corrosion of aluminum.

Hasten. 2al +6hcl ==== 2alcl₃+ 3h₂↑<

The reaction between aluminum and water is 2Al+6H2O=2Al(OH)3+3H2, and the essence of the reaction: water is a very weak electrolyte, but hydrogen ions and hydroxide ions can be ionized in water to react with aluminum to form Al(OH)3 and H2. The reaction conditions can be heated or carried out at room temperature, and it is difficult to observe the phenomenon at room temperature.

However, under the action of chloride ions, the dissolution of the oxide layer on the surface can be accelerated. Accelerating the reaction, i.e. aluminium will corrode in brine.

Salt water is a neutral solution, and the metal will be corroded by oxygen absorption in a neutral solution, which is electrochemical corrosion.

The reaction between aluminum and water is 2Al+6H2O=2Al(OH)3+3H2, and the essence of the reaction: water is a very weak electrolyte, but hydrogen ions and hydroxide ions can be ionized in water to react with aluminum to form Al(OH)3 and H2. The reaction can be heated or carried out at room temperature, and it is difficult to observe the phenomenon at room temperature.

However, the dissolution of the surface oxide layer can be accelerated under the defeat of chloride ions. The reaction is accelerated, i.e. the aluminum will corrode in the brine search.

The salt water corrodes the aluminum metal, and the oxide film on the surface of the aluminum alloy material is susceptible to chloride ions.

, which causes galvanic corrosion.

phenomenon. Corrosion of metal materials in contact with the electrolyte solution through electrode reactions. The electrochemical corrosion reaction is a redox reaction.

In the reaction, the metal loses electrons and is oxidized, and its reaction process is called the anode reaction process, and the reaction product is the metal ions that enter the medium or the metal oxide (or metal insoluble salt) covering the metal surface; The substance in the medium is reduced by gaining electrons from the surface of the metal, and its reaction process is called the cathodic reaction process.

Summary. Hello, dear, glad to answer for you! How does salt corrode aluminum?

Title. Under normal circumstances, there is a dense oxide film on the surface of the aluminum, which has a protective effect on the aluminum. When salt is present, salt can ionize Na+ and Cl- in humid air, and Cl- is easy to react on the surface of the oxide film to form adsorption compound AlCl3, which is soluble in water and cannot form a dense protective film, so the aluminum container will be corroded when it comes into contact with salt.

How does salt corrode aluminum? Title.

Dear, Oak Jean Hello, glad to answer for you! How does salt corrode aluminum? Title.

Under normal circumstances, there is a dense oxide film on the surface of the aluminum, which has a protective effect on the aluminum. When there is table salt, the salt can ionize Na+ and Cl- in the humid air, and Cl- is easy to react on the surface of the oxide film to form the adsorption compound AlCl3, AlCl3 is easily soluble in water, and the bridge can form a dense protective film, so the aluminum container will be corroded in contact with the salt.

Aluminium has a high metal activity and is displaced by the cations of certain salts.

There is no recipe.

Pro-1) Haoheng first reacts with the oxide film on the surface (Oxygen Yousen does aluminum): Al2O3 + 6HCl = 2ALCL3 +3H2O 2) and then reacts with the metal aluminum inside the spring companion: 2Al+6HCl=22AlCl3 +3H2