The problem of the coexistence of a large number of ions, the coexistence of a large number of ions

1 NH4+ +OH- = NH3 +H2O (ammonia monohydrate) HCO3- +OH- = H2O +CO3(2-)2 H+ and NO3- to form nitric acid, which has strong oxidizing properties, oxidizes Fe2+ to Fe3+3 CH3COO- +H+ = CH3COOH (can not coexist in the solution to form weak acid and weak reduced ions).

NH4+, OH- together form ammonia, Fe2+, NO3- one has strong reducing properties, and the other has strong oxidizing properties.

ch3coo-，.H+ will react.

3 is right. , NH4+, HCO3-, OH-OH- reacts with HCO3- to form CO3

NH4+,OH- cannot coexist in large quantities and will form ammonium gas.

fe2+,no3-,so4(2-)

H+, NO3- is nitric acid that oxidizes ferrous ions.

[NH4+]+OH-] = NH4OH (weak electrolyte, decomposes in case of heat) = NH3 + H2O

HCO3-]+OH-]=[(CO3)2-]+H2O, so it cannot coexist.

It can coexist at room temperature. When heated, [Fe2+] is oxidized by [(NO3)-]SO4)2-].

H+]+AC-]=HAC (weak electrolyte) AC- is an abbreviation for acetate ions, so they cannot coexist.

Strong acids and strong bases cannot coexist, and the colors are usually transition metal ions (such as copper ions, iron ions, etc., which will form precipitates when exposed to alkali or carbonate solutions), and generally do not interact with alkalis. Carbonate ions coexist. The key to the coexistence of ions is to see whether there is precipitation or gas formation

1.Alkali metals can be present in acidic or alkaline media, and can also coexist with most anions.

2.Alkaline earth metal ions cannot coexist with hydroxide ions, carbonate ions, and sulfate ions (except magnesium ions).

3.Transition metal ions cannot coexist with alkalis, carbonate phosphates, but can coexist with sulfate ions.

4.Carbonates cannot coexist with acids, and strong oxidants cannot coexist with strong reducing agents. Wait a minute.

Giving a strong acid indicates that there is a large amount of H+ in the solution, and note ions that cannot coexist with H+, such as CO32-.

Giving a strong base indicates that there is a large amount of OH- in the solution, pay attention to ions that cannot coexist with OH-, such as Fe2+.

The general color means that the solution is colorless, but colored ions such as Cu2+ are given in the options, which is contrary to objective facts and is also judged to be impossible to coexist in large quantities.

The common substances in chemistry are given strong acids, strong bases, and colors in order to narrow down the range of substances, especially the color, which can best judge what kind of substance it is.

No precipitation, water, or gas generation.

1.Carbonate, bicarbonate, hydroxide, metaaluminate, weak acid (such as acetate), cuprous ion, etc.

2.Hydrogen ions, which produce precipitated ions (such as iron ions), bicarbonate, etc.

3.bicarbonate, etc.

4.It depends on what color it is, blue is generally copper ions, and hydroxide, carbonate, sulfur ions, etc. cannot coexist. Yellow is generally ferric ions, sulfur ions, carbonates, hydroxides, reducing ions (such as iodine ions), metaaluminate, etc. can not coexist.

Purple-black is generally permanganate, and reducing ions cannot coexist.

5.Metaaluminate, carbonate (produces aluminum hydroxide and carbon dioxide), a small amount of hydroxide, etc.

6.Aluminum ions, ferric ions, hydrogen ions.

Thiby ions), I'm just a freshman in high school, I don't know anything about complexation reactions, I only know such a thing.

8.Reducing ions, such as iodine ions.

9.Oxidizing ions, such as permanganate, nitric acid, concentrated sulfuric acid, hypochlorous acid, etc.

Weak alkali cannot coexist with hydroxide group.

Weak acids cannot coexist with hydrogen ions.

Weak acid roots cannot coexist with weak base roots (dihydrolysis).

1.Hydroxide, sulfide ions, thion.

2.Hydrogen ions, hydrogen thion, sulfide.

3.Hydrogen thion, sulfide.

4.In potassium permanganate: hydroxide trivalent iron ions: hydroxide and so on5Bicarbonate.

6.Hydrogen ions: Iron ions.

7.Metaaluminate.

8.Thiogen, 9

Sodium, chloride can be.

Nitrate ions, sulfate ions are not.

The production of hydrogen from aluminium can be a strong alkali or a dilute acid.

NaOH and hydrochloric acid can.

Concentrated nitric acid and concentrated sulfuric acid are oxidizing and do not produce hydrogen.

There is nitric acid and the existence of an acidic environment, isn't it equivalent to nitric acid, have you figured it out?

The answer to your question is this. For your analysis, aluminum can be combined with strong acid (hydrochloric acid, dilute sulfuric acid) or strong alkali (sodium hydroxide) to release hydrogen at room temperature. Corresponding to your conditions, adding metal aluminum and releasing hydrogen gas, then these are the two possibilities.

However, it is important to emphasize here that the reaction of nitric acid and metal aluminum does not release hydrogen. Looking at the second condition, there are sodium ions, chloride ions, nitrate ions, and sulfate ions. Then there are two possibilities, the first is the strong acid celery burning solution, because we all know that strong acid and sodium salt are completely ionized in the aqueous solution, so according to the first condition, after adding metal aluminum, will hydrogen be released?

The answer is no. There are nitrate ions, and the reaction produces water, as well as nitric oxide gas. The second is a strong alkali solution, in the strong alkali (according to the title, the strong alkali here is also sodium hydroxide) solution, the sodium and sodium salt are also completely ionized, and the above ions can coexist in large quantities, so when you add metal aluminum, metal aluminum can react with sodium hydroxide to generate sodium metaaluminate and hydrogen.

Therefore, the above ions can coexist in a strong alkaline solution that can release hydrogen gas after adding metal aluminum.

AB PO43- was selected as the weak acid ion.

C mno4 - colored.

D Fe2+ and NO3- can not coexist, Fe2+ has a color, NH4+ in A can exist in large quantities in acidic solution, but not in alkaline.

MgSO4 white precipitate is generated.

The color is acidic, colored.

It should be that the medium phosphoric acid is a weak acid, and the phosphate group cannot coexist with hydrogen ions.

The permanganate in C is purple-red, the ferrous ions in D are green, and in the strong acid environment, there are nitrates, and the ferrous ions will be oxidized.

Mg2+, SO42- in A will generate MgSO4 white precipitate, and PO43- in B is a weak acid root that will be hydrolyzed.

The mno4- in c is colored, is purplish-red, and does not match the title of the ancient selection d

a Magnesium sulfate white precipitate.

b Correct. c Permanganate purple under acidic conditions.

d Acidic conditions: nitrate roots are oxidized, and divalent iron ions are oxidized.

a Correct.

b Phosphoric acid is a difficult ionization substance.

C NO3- has strong oxidation with H+ can not coexist with MNO4-, a large amount of NO3- in D, strong oxidation with H+ can not coexist with FE2+ in large quantities.

One. If the topic requires a colorless solution, non-ferrous ions, acid ions or non-metallic elemental molecules I2 such as Cu2+, Fe3+, Fe2+, MnO4-, Fe(SCN)2+, Fe(C6H5O) 63-, etc., cannot coexist in large quantities.

Two. Refers to alkaline, acidic. In the case of an acidic solution, all weak acid ions and OH- cannot coexist in large quantities.

The ions that cannot coexist in acidic solution in middle school chemistry are: oh-, alo2-, CO32-, HCO3-, SIO32-, SO32-, HSO3-, S2O32-, S2-, HS-, clo-, F-, PO43-, H2PO4-, C6H5O-, CH3COO-、-OOC-COO-, C6H5COO-, CH3CH2O-, SCN-, H2N-CH2-COO-, etc. If it is an alkaline solution, all weak base cations and H+ cannot coexist in large quantities. In secondary school chemistry there can be no co-existence in large quantities in alkaline solutions are:

H+, Fe2+, Fe3+, Cu2+, AG+, Zn2+, Mg2+, Al3+, NH4+, HCO3-, HPO42-, H2PO4-, HSO3-, HS-, Hooc- CoO-, etc.

Ions directly combine with each other to form insoluble substances (such as AGCL, AGBR, BaSO4, etc.), gases (such as NH3, CO2, etc.) or weak electrolytes (such as H2O, HF, H2S, etc.) cannot coexist in large quantities in the same solution.

If two ions meet, they cannot coexist if they undergo a redox reaction. Such as Fe3+ and S2-, Fe3+ and I-, Fe2+ and No3- (H+), etc.; Mno4-, No3- (H+), Clo- (H+), Cr2O72- did not coexist with S2-, I-, SO32- and Fe2+. SO32- and S2- do not coexist under acidic conditions. Due to the double hydrolysis reaction between weak base cations and weak acid anions, they cannot coexist, such as Al3+ does not coexist with CO32-, SO32-, HCO3-, HSO3-, HS-, and ALO2-. AlO2- does not coexist with Fe3+, Fe2+, Zn2+, Cu2+, AG+, NH4+; SiO32- does not coexist with NH4+.

If complexation occurs between ions to form complex ions, these ions cannot coexist. For example, Fe3+ and SCN- do not coexist; Ag+ does not coexist with NH3·H2O molecules; ag+ and cn- do not coexist. That's pretty much it, just memorize it.

Except for those in junior high school, they cannot coexist due to metathesis reactions.

It is also necessary to consider the situation where coexistence cannot occur due to redox reactions.

Hello, the reason why the n-trivalent aluminum ions and sulfide ions cannot coexist is that double hydrolysis occurs.

2al3++3s2-+6h2o==2al(oh)3 +3h2s (the plus sign may not be displayed, this is a problem with my mobile phone, please forgive me!) In addition, there are positive trivalent silver ions, but they cannot be present alone in aqueous solutions, but need to be stabilized by a coordination reagent, such as f-. There is a mineral in nature, which is ago, and silver here is not a positive second price, but a positive one price and a positive third price.

Hope it helps!

If you don't understand, please ask!

Are you sure you have +3 valence silver ions in the question?

3-valent silver ions have strong oxidizing properties and can oxidize S2-, so they cannot coexist, but +3-valent silver ions are generally not seen, and can only be prepared with particularly strong oxidants.

Aluminum sulfide solids are present, but double hydrolysis occurs in water and therefore cannot coexist.

al2s3+3h2o==al（oh)3↓+3h2s↑

Why can't valence silver ions and negative divalent sulfide ions.