Derivation of the double hydrolysis equation for aluminium and metaaluminate ions5

Al(3+) 3H O == Al(OH) 3H(+) Aluminum ion hydrolysis, one aluminum ion combined with 3 hydroxide ions.

One Al(OH) is generated, and 3 hydrogen ions remain.

alo (-h(+)h o == al(oh) metaaluminate ion.

Hydrolysis. Metaaluminic acid cannot react with Co. But if it's a metaaluminate solution, it's fine. Because metaaluminic acid is less acidic than carbonic acid, it is equivalent to replacing weak acid with strong acid, (taking sodium metaaluminate as an example) to produce sodium carbonate and aluminum hydroxide.

Precipitation, if CO is excess, produces sodium bicarbonate.

and aluminum hydroxide precipitation.

<> hydrolysis of aluminum ions, one aluminum ion combines 3 hydroxide ions to generate an Al(OH)3 with 3 remaining hydrogen ions.

Metaaluminate ions.

Hydrolysis, in which a metaaluminate ion binds to a hydrogen ion (which can be thought to be a hydrogen ion produced by the hydrolysis of aluminum ions) while binding a water molecule.

Generate an aluminium hydroxide.

It can be seen as a reaction between metaaluminic acid and water, due to the hydrolysis of aluminum ions to produce 3 hydrogen ions, and a metaaluminic acid only combines one hydrogen ion (or hydrolysis to form a hydroxide), natural acid-base neutralization.

Aluminum ions combine hydroxide ions in water to form aluminum hydroxide precipitates, and metaaluminate memory combines hydrogen ions in water to form aluminum hydroxide precipitates. Precipitation is continuously generated, which promotes the positive movement of the reaction.

Al(3+) 3H2O ==Al(OH)3 + 3H(+) aluminum ion hydrolysis, one aluminum ion combines 3 hydroxide ions to form an Al(OH)3, and the remaining 3 hydrogen ions;ALO2(-)H(+)H2O ==AL(OH)3 metaaluminate ion hydrolysis, a metaaluminate ion binds to a hydrogen ion (it can be considered as a hydrogen ion produced by the hydrolysis of aluminum ions), and at the same time combines a water molecule to generate an Al(OH)3, since Al(3+) hydrolysis produces 3 hydrogen ions, and an ALO2(-) only binds one hydrogen ion, so the coefficient of ALO2(-) should be expanded to 3, so that AL(3+) The 3 hydrogen ions produced by hydrolysis are all obtained by ALO2(-), and the 3 halo2s generated at the same time are combined with 3 H2O molecules to generate 3 Al(OH)3, plus 1 Al(OH)3 generated by Al(3+) hydrolysis, a total of 4 Al(OH)3, so the equation for Al(3+) and ALO2(-) double hydrolysis is: Al(3+) 3alo2(-)6H2O ==4AL(OH)3 The second balancing method is very simple, It is the method of conservation of charge, that is, according to the total charge in the equation is zero, the charge is distributed first, and then the atom is al(3+) alo2(-)h2o ==al(oh)3 al(3+) 3alo2(-)h2o ==al(oh)3 al(3+) 3alo2(-)h2o ==4al(oh)3 al(3+) 3alo2(-)6h2o ==4al(oh)3

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.

H+ ion small amount: AlO2-+H+ +H2O= Al(OH)3 H+ ion excess: AlO2-+4H+ = Al3++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.

al3+ +3alo2 - 6 h2o = 4 al(oh)3

Aluminum ions can be hydrolyzed with partial aluminum, and aluminum is double hydrolyzed, and aluminum is not hungry.

The reaction of aluminum ions and metaaluminate with water is essentially double hydrolysis.

1) Al(3+) 3H2O = Reversible = Al(OH)3 + 3H(+).

2) AlO2(-)2 H2O = Reversible = Al(OH)3+OH(-).

1)+(2)x3 about 3 h2o( 3h(+)3oh(-)3h2o).

It yields: Al(3+) 3alo2(-)6H2O ==4Al(OH)3

The first step is the reaction of aluminum ions and hydroxides to form metaaluminate and water: Al3+ +4OH- (excess) = ALO2- +2H2O

The second step is metaaluminate and hydrogen ions to produce aluminium from the culture of the preparation and water: alo2- +4h+ (excess) = al3+ +2h2o

This is the reaction of adding excess acid-base inter-conversion, and it cannot be added without the formation of Al(OH)3.

I hope it can help you, 8, the ion equation of aluminum ion and metaaluminate and water reaction, find the equation step by step process, I remember that the first step is the reaction of aluminum ions and hydroxide to generate metaaluminate and water, the second step is metaaluminate and hydrogen ions to generate messy slag aluminum ions and water with accompaniment, addition and addition can not come out of this equation al3++3alo2-+6h20=4al(oh)3 (arrow),

alo2- +nh4+ +h2o=al(oh)3 ↓+nh3↑

Or search for a shortage: the world debate.

ALO2- +NH4+ +2H2O=AL(OH)3 Lead +NH3·H2O