Metaaluminate reacts with aluminum ions to produce something

Add weak acids or a small amount of strong acids (in the case of hydrochloric acid).

Naalo2+HCl+H2O====Al(OH)3(precipitation)+NaCl ion equation:

alo2-）

H+)+H2O====Al(OH)3 (precipitation) plus excess strong acid (take hydrochloric acid as an example).

Naalo2+4HCl====AlCl3+NaCl+2H2O ion equation:

alo2-）+

4h+）====（al3+）

2H2O does not react with alkali!!

Aluminum ions react with an excess of a strong alkaline solution to form metaaluminate.

For example: the properties of AlCl3+4NaOH=Naalo2+2H2O+3NaCl metaaluminate are expressed by the ionic equation as follows:

Metaaluminate solution undergoes a hydrolysis reaction, and the solution is alkaline.

alo2-2h2o

al(oh)3

OH-metaaluminate reacts with acid.

Reaction with strong acids: moderate amount of strong acids:

alo2-h+

h2o==al(oh)3

Excess strong acid: alo2-

4h+=al3+

2H2O reacts with a weak acid (H2CO3): that is, CO2 gas is introduced.

Moderate amount of CO2:

2alo2-

co2+3h2o==2al(oh)3

CO32 - Excess CO2:

AlO2-CO2+2H2O==Al(OH)3HCO3-aluminum salt reacts with metaaluminate solution:

al3+3alo2-

6h2o==4al(oh)3

Metaaluminate can also be understood as an amphoteric al-alkaline salt.

The reaction equation for aluminum ions and metaaluminate ions is: Al3+ +4OH- (excess) = AlO2- +2H2O.

Metaaluminic acid is an inorganic substance with the chemical formula halo2. Soluble in water, insoluble in ethanol. Metaaluminic acid is a weak acid, an acid that is weaker acidic than carbonic acid. It is used as a mordant for textiles, a filler for paper, a purifying agent for water, etc.

But if it's a metaaluminate solution, it's fine. Because metaaluminic acid is less acidic than carbonic acid, it is equivalent to the replacement of weak acid by strong acid, (taking sodium metaaluminate as an example) to generate sodium carbonate and aluminum hydroxide precipitation, and if CO2 is excessive, sodium bicarbonate and aluminum hydroxide precipitation will be generated.

Sodium metaaluminate:

Sodium metaaluminate exists in the form of Na[Al(OH)4] in aqueous solution, which was abbreviated as Naalo2 for convenience. But its actual composition is still na[al(OH)4]. Naalo2 sodium metaaluminate is shorthand as the hydrogen ion (H+) is actually the hydronium ion.

What is actually present in the solution is Na[Al(OH)4]. This is a coordination compound, which is involved in a chemistry competition, but in high school textbooks it is abbreviated as naalo2. Similarly, [Zn(OH)4]2-, [Fe(OH)4]-, etc., are actually two compounds.

with different compositions and structures.

The equation for the reaction of aluminum ions with metaaluminate ions is given below:

The reason why AL +3alo +6h o=4AL(OH) aluminum ions cannot coexist with metaaluminate ions in solution is that aluminum ions react with metaaluminate ions.

Because the acidity of metaaluminic acid is weaker than that of carbonic acid, it is equivalent to the replacement of weak acid by strong acid, (taking sodium metaaluminate as an example) to generate sodium carbonate and aluminum hydroxide precipitation, if CO is excessive, sodium bicarbonate and aluminum hydroxide precipitation will be generated, metaaluminate can react with excess hydrogen ions (strong acid) to form trivalent aluminum ions.

Aluminum and hydrochloric acid: 2Al+6HCl=2AlCl +3H Aluminum and sodium hydroxide: 2Al+2NaOH+H O=2Naalo +3H Aluminum hydroxide pyrolysis:

2Al(OH) = AL O +3H O Alumina & Hydrochloric Acid: AL O3 6HCl = 2ALCL +3H O Alumina & Sodium Hydroxide: AL O +2NaOH = 2Naalo +H O Alumina & Hydrochloric Acid:

Al(OH) +3HCl=ALCL +3HOSodium metaaluminate, chalin and hydrochloric acid: Naalo +4HCl=AlCl +NaCl+2HO

Aluminum chloride and sodium metaaluminate: AlCl +3Naalo +6HO=4Al(OH) 3NaCl

Aluminum is a light metal with the chemical symbol AL and atomic number: 13. The content of aluminum in the earth's crust is second only to oxygen and silicon, ranking third, and it is the most abundant metal element in the earth's crust, and its reserves are the second in the metal.

Among the metal varieties, it is the second largest group of metals after steel.

Aluminum is soluble in dilute sulfuric acid, dilute nitric acid, hydrochloric acid, sodium hydroxide and potassium hydroxide solutions, insoluble in water. The ionic equation for the reaction of aluminum with hydrochloric acid is 2AL + 6H+ +6Cl- =2AL + 6Cl- +3H

Aluminum is soluble in dilute sulfuric acid, dilute nitric acid, hydrochloric acid, sodium hydroxide and potassium hydroxide solution, insoluble in water, but can react slowly with hot water to form aluminum hydroxide, relative density, elastic modulus 70gpa, Poisson's ratio.

Acid salts of strong acids, such as sodium bisulfate, should be divided into sodium ions, hydrogen ions and sulfate ions (only bisulfate belongs to this category in high schools); Weakly acid salts such as sodium bicarbonate are split into sodium ions and bicarbonate ions (acid salts such as carbonic acid, phosphoric acid, and sulfurous acid are all of this type).

The ionic equation for the reaction of aluminum with hydrochloric acid is given below

2al + 6h+ +6cl- =2al₃+ 6cl- +3h₂↑

1. "One write": first write the chemical equation of the reaction based on objective facts

2al+6hcl ==2alcl₃ +3h₂↑

2. "Two changes" (or dismantling): rewriting substances that are easily soluble in water and easy to ionize into ionic form (the most critical step):

2al + 6h+ +6cl- =2al₃+ 6cl- +3h₂↑

3. "Three deletions": Delete the ions on both sides of the equation that do not participate in the reaction:

2al + 6h+ =2al3+ +3h₂↑

4. "Four checks": check whether the number of atoms and the total number of charges of each element on both sides of the ion equation are equal.

3alo2-+al3++6h2o==4al3。

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

The surface of the immediate formation of a dense oxide film with a thickness of about 50 angstroms (1 angstroms = nanometers), so that the aluminum will not be further oxidized and can resist water, but the powder of aluminum mixed with air is extremely flammable, and the molten aluminum can correspond violently with water, aluminum is amphoteric and very soluble in strong alkalis, and can also be soluble in dilute acids.

The structure of aluminum reagents is complex, and the equation is difficult to represent.

The aluminum reagent is 3-(bis(3-carboxy-4-hydroxyphenyl)methylene)-6-oxo-1,4-cyclohexen-1-carboxylate triammonium. In a weakly acidic solution, Al3+ aluminum reagent reacts to form a rose-red substance.

Look at this, you don't have to write equations.

Aluminium can react with bases to form metaaluminate compounds.

Knowledge point analysis:

A common reaction is the reaction of aluminum with strongly basic sodium hydroxide (NaOH) or potassium hydroxide (KOH) to form metaaluminate ions.

The reaction equation is as follows:

2al + 2naoh + 6h2o 2na[al(oh)4] +3h2

In this reaction, aluminum reacts with hydroxides to form metaaluminate ions (Na[Al(OH)4]) and hydrogen is released at the same time.

Application of knowledge points:

1.Metaaluminate ions are widely used in the production process of Portland cement and glass in the chemical industry as thickeners, preservatives, etc.

2.Metaaluminate ions can also be used in wastewater treatment as a precipitant to remove heavy metal ions from wastewater.

Example Explanation:

Question: When 5g of aluminium is added to an excess sodium hydroxide solution, what is the number of moles of metaaluminate ions generated?

Answer: According to the reaction equation, it can be known that 2 mol of aluminum and 6 mol of sodium hydroxide react to form 2 mol metaaluminate ions.

First, calculate the number of moles of aluminum:

The relative atomic mass of aluminium is 27 g mol, so the molar number of 5 g of aluminium is:

5 g / 27 g/mol ≈ mol

Since sodium hydroxide is excessive, the molar ratio is 1:3, and the number of moles of metaaluminate ions is 1 2 mol of aluminum:

mol × 1/2) = mol

So, the number of moles of metaaluminate ions produced is about mol.