A group of ions that can be present in large quantities in a colorless solution at pH 5 is

pH = 5, acidic, A error, Cu2+ colored, blue and colorless do not match.

B error, Ag+ and Cl- will generate AgCl precipitate.

c error, Ba2+ and SO42- will generate BaSO4 precipitate.

D correct solution.

pH 5 acidic has a certain amount of H+

Colorless A has Cu2+ Blue excluded.

b Silver ions and chloride ions will form precipitates for exclusion.

c Carbonate ions will react with H+.

D correct can coexist in large quantities.

Colourless.. a。。Copper ion blue. Delete.

b。。Silver and chloride ions form precipitates. Delete.

c。。Carbonate ion and hydrogen ion reaction... Delete.

So choose D.

Answer: DA: There are copper ions, and the copper ions are blue, so no.

b: There are anions and chloride ions, which will form silver chloride precipitates.

c: Barium ions will form precipitates with carbonate ions and sulfate ions.

D: Can coexist in large quantities.

Answer: DA copper ions are green, which is contrary to colorlessness.

bSilver and chloride ions form precipitates.

Barium ions and carbonate will precipitate, and pH=5 is acidic, and carbonate cannot be present.

Maybe it's A, I'm not very good at chemistry, don't spray if it's wrong.

d: silver ion, sodium ion, barium ion, nitrate ion.

Choose ab Some chemistry questions can be double-selected.

a. Correct. It can coexist and is a colorless solution.

b. Correct. It can coexist and is a colorless solution.

c. Error. Ba2+ reacts with SO42- to form a white precipitate of BaSO4, and Cu2+ is blue.

d. Error. H+ reacts with OH- to form H2O, which does not coexist.

A and B members of the math tutoring team will answer for you, please correct any mistakes, and please ask if you don't understand.

If there is no problem, just take it, I really hope it will help you in your study or life!

A can be B can also have precipitation D have water generation can not coexist in large quantities.

Depressed!! Of course we can coexist!!

It is KCl solution that will be generated, but KCL (colorless clear solution, no precipitation) is composed of Cl- and K+. In the KCl solution, Cl- and K+ exist in ionized form, that is, Cl- and K+ are still the same as they were, and they can coexist without change.

In addition: A, HCO3- will react with H+, and the production of H2O, CO2B, Fe3+ is brownish-yellow, so it cannot be in a colorless solution.

D. Ca2+ and CO32 produce white precipitate.

It cannot coexist because of the formation of gases or precipitates or colloids or microdissolves between ions in the solution

Cl- and K+ form KCl, which is still K+ and Cl- in solution, unlike Ca+ and CO32- can form a white precipitate CaCO3 in solution

KCl is completely ionized into K+ and Cl- in water

Potassium ions and chloride ions in KCl solution are in ionic form, not in KCL molecular form. This one involves the question of strong and weak electrolytes. Potassium salts are fully soluble.

KCl is a strong electrolyte that is completely ionized in aqueous solution and exists in ionic form. So there are no KCl molecules in the KCL solution, only potassium ions and chloride ions. Only in weak electrolyte solutions do solute molecules and ions coexist.

A H+ and HCO3- react to produce water and CO2 B Fe3+ is yellow, and the stem is required to be a colorless solution.

D Ca2+ CO32- reaction to generate CaCO3 precipitate c correctly. Analysis: Inability to coexist refers to a significant reduction in ion concentration due to reaction after ion encounter.

The situation of non-coexistence in junior high school is mainly metathesis reaction, which must be able to generate: water, gas, and precipitation, so that it cannot coexist.

There is no precipitation or gas.

And the solution is colorless.

This type of question is given points.

As long as gas can be generated. Water, precipitation, and ions cannot coexist.

C Explanation: A component reacts to carbon dioxide; Component B ferric is hydrolyzed and is not colorless; d reaction into a precipitate.

The question here is that I have actually done it in a cup.

Well. KCL is generated, but potassium chloride is soluble in water, so it is still an ion.

1) After the reaction between the solution and Al2O3, Al3+ is formed, then the original solution must contain H+ (because alumina will react under acidic conditions to form Al3+: Al2O3 + 6H+ =2Al3+ +3H2O), and it must not contain a large amount of HCO- (because if there are hydrogen ions in the solution, and then there are bicarbonate ions, the two will react to form carbon dioxide: H+ +HCO3- =H2O+CO2).

2) After the reaction between the solution and Al2O3, there is ALO2- generation, then the original solution must contain OH- (because alumina will react under alkaline conditions to form ALO2-:Al2O3 + 2OH- =2ALO2- +H2O), which may contain a large amount of Na+ (because there are hydroxide ions in the solution, the cations that can be matched should be considered next, sodium ions and hydroxide ions can coexist, and Mg2+, Ag+ react with hydroxide to form water-insoluble precipitates).

3) Write the ion equation for the reaction of the solution with AlO2O3 to form ALO2-.

al2o3 + 6h+ =2al3+ +3h2oal2o3 + 2oh- =2alo2- +h2o。

Answer] D Answer Analysis] Test Question Analysis: If there is a chemical reaction between ions, it cannot coexist in large quantities, and vice versa. A, H reacts with HCO3 to form CO2 and water, which cannot coexist in large quantities, and A is incorrect; B. Iron is orange-yellow in solution, and Fe3 reacts with i to form elemental iodine, which cannot coexist in large quantities in ferrous ions, and B is incorrect; C, NH4 reacts with OH to form ammonia water, which cannot coexist in large quantities, and C is incorrect; D. K+, SO42, S2 spring type, and Cl can coexist in large quantities in solution, D is correct, and the answer is D.

Test Center: Examine the true and false judgment of ion coexistence.

a. There is no reaction between magnesium ions, hydrogen ions, chloride ions, and potassium ions, and a large number of coexists, and there are no color-developing ions, so the option is correct;

b. There is no reaction between copper ions and hydrogen ions, chloride ions, and potassium ions, and a large number of them can coexist, but copper ions are blue in the solution, so the option is wrong;

c. Hydroxide ions will form water with hydrogen ions, which cannot coexist, so the option is wrong;

d. Carbonate ions and hydrogen ions will form carbon dioxide gas and water, which cannot coexist, so the choice is wrong;

So the option is: a

It cannot coexist in large quantities, and CR2O72- is orange-yellow.

In alkaline solutions, they can coexist in large quantities.

Hydrogen is released by reacting with aluminum, and the solution is alkaline or acidic, and the magnesium ions and hydroxide generated by magnesium ions and hydroxide in the alkaline solution cannot exist in large quantities, and a large number of coexists in the acidic solution.

The concentration of hydrogen ions ionized by water is 10 -13mol l, and the solution is acidic or alkaline, and they can all coexist in large quantities.

The solution is heated with sodium hydroxide to generate gas and precipitation, indicating that there are ammonium ions and insoluble alkali cations in the solution.

If there are aluminum ions in the solution, metaaluminate ions and bicarbonate ions cannot exist in large quantities, and if there are iron ions in the solution, bicarbonate ions cannot exist in large quantities.

Metaaluminate ions react with ammonium to form ammonia monohydrate and aluminum hydroxide precipitate, metaaluminate cannot exist in large quantities.

The solution turns the phenolphthalein solution red, the solution is alkaline, and they can coexist in large quantities.

See if the reaction produces precipitation, gas you or water, and produces does not coexist.

Answer: If there is a chemical reaction between c ions, it cannot coexist in large quantities, and vice versa. BA2+ and SO3

Generate. Barium sulfite.

Precipitation, SIO3 "No Wheel Sub>2

and H+ to generate silicic acid precipitate, and Shen Fiber Cu2+

It appears blue in solution. So.

Correct answer. Yes c.

b carbonate ions and hydrogen ions will form carbonic acid, and carbonic acid will decompose into water and carbon dioxide.

There are bicarbonate and hydroxide ions in C, the former will form carbonic acid, the latter will form water, and in D, hydroxide and hydrogen ions will form water and cannot coexist.

So the answer is A

A is true, B is false, CO32 - +H+=HCO3-, HCO3 - +H=H2CO3, C is wrong HCO3 - +H=H2CO3, D is wrong CH3COO-+H+=HCOOH, H++OH - =H2O