When writing ionic equations, which ones can be taken apart

Regularity features. 1.Weak electrolytes cannot be disassembled. For example: water,Acetic acid, etc. (weak acid, weak base).

2.Oxides are basically not disassembled, and CO2 is not an ionic compound.

Iron oxide is insoluble and precipitates, so it can't be disassembled, in short, you remember, when you see oxide, it's best not to dismantle it.

3.Gases, elemental matter, you're right, don't think about dismantling these things when you see them, because they are all molecular structures or atomic structures.

Since it is to write ionic compounds, only soluble ions that can move freely in solution can be dismantled, typical of which are chlorination and nitric acid.

Wait. Weak electrolytes can not be disassembled, such as: water, acetic acid, etc. (weak acid, weak alkali), oxides can not be disassembled, CO2, iron oxide can not be disassembled, gas, elemental substances can not be disassembled, precipitation can not be disassembled, detachable has strong electrolytes that are easily soluble in water, such as strong acids and strong alkalis can be dissolved in water salts.

Absolutely not disassembled: water precipitation, gas oxides, elemental complexes such as ferric thiocyanide, lead acetate, non-electrolytes (such as ethyl alcohol), weak electrolytes (such as acetate ammonia monohydrate).

To be dismantled: Soluble salts other than ferric thiocyanide and lead acetate, dilute sulfuric acid, nitric acid, hydrobromide, hydroiodic acid, hydrobromide, iodic acid, alkali formed by alkali metals below sodium on the periodic table, clear lime water.

Concentrated sulfuric acid does not dismantle hydrofluoric acid, does not dismantle lime milk, and weak alkali does not dismantle (but sometimes depending on the situation, for example, the sodium bicarbonate in Hou-style alkali is not dismantled, because it is a precipitation).

The substances that cannot be disassembled by the ionic equation are:

1. Weak electrolytes cannot be disassembled, such as: water, acetic acid and other weak acids, ammonia monohydrate and other weak alkalis. Soluble strong electrolytes (strong acids, strong bases, soluble salts) are all indicated by ion symbols, and other insoluble substances.

Substances that are difficult to ionize, gases, oxides, water, etc., are still expressed by chemical formulas.

2. Oxides cannot be disassembled, such as CO2 and iron oxide are precipitated and cannot be disassembled.

3. The gas cannot be disassembled. Gases are all molecular or atomic structures, and to write ionic compounds, only soluble deviators that can move freely in solution can be dismantled.

Detachable: strong acids, strong alkalis, and soluble salts are detachable.

Non-disassembleable: weak acid, weak alkali, water (the three can be collectively referred to as weak electrolytes), insoluble salts, gases, elementals, oxides can not be disassembled.

There is also the problem of microsolubility.

It depends on whether it is in the reactant or the product.

If it is a reactant: it depends on whether it is a clear liquid or a turbid liquid, the clear liquid can be disassembled, and the turbid liquid cannot be disassembled.

If the spawn is not dismantled. For example, calcium hydroxide.

If the lime water is clarified, it must be disassembled, and if the lime milk is not opened.

This place is mainly about memorizing what kind of material this kind is.

1. Weak electrolytes cannot be disassembled, such as: water, acetic acid and other weak acids, ammonia monohydrate and other weak alkalis.

2. Oxides cannot be disassembled, such as CO2 and iron oxide are precipitated and cannot be disassembled.

3. The gas cannot be disassembled. Gases have a molecular structure or an atomic structure, and to write ionic compounds, only soluble ions that can move freely in solution can be dismantled.

In the aqueous solution, strong acids, strong alkalis, and soluble salts can be dismantled; The substances that can be dismantled must be strong electrolytes, but there are also substances that cannot be dismantled in strong circular electrolytes. For example, the common ones cannot be dismantled by insoluble salts, concentrated sulfuric acid (concentrated sulfuric acid is a covalent compound, and covalent compounds need to be ionized in an aqueous solution), and active metal oxides cannot be disassembled.

In addition to strong electrolytes, there are also common water, gases, and elemental substances that can not be dismantled. For substances that cannot be disassembled, let him keep the original chemical formula in the equation without changing.

Strong electrolytes are detachable because strong electrolytes are all ionized in solution. Seriyama tells that weak electrolytes are not detachable, and most of them are molecules. Precipitated, water-insoluble substances are not detachable.

For example: (the ion equation is written as ions by the chemical equation to write the strong electrolyte that can be ionized as ions, and then the same ions are eliminated on both sides, only one example is given in the front, and the latter is omitted) sodium hydroxide and sulfuric acid reaction: 2NaOH + H2SO4 ==Na2SO4 + 2H2O2Na+ +2OH- +2H+ +SO42- =2Na+ +SO42- +2H2O to eliminate the same ions:

2OH - +2H+ = 2H2O i.e. OH- +H+ = H2O Sodium hydroxide and acetic acid reaction: OH- +HAC ==AC- +H2O Barium hydroxide and sulfuric acid reaction: 2OH- +BA2+ +2H+ +SO42- =BASO4 + 2H2O Note not:

OH- +Ba2+ +H+ +SO42- =BASO4 + H2O (because ions have a proportional relationship, it can be seen by writing the chemical equation) Copper oxide and sulfuric acid reaction: Cuo + 2H+ =Cu2+ + H2O Copper hydroxide and sulfuric acid reaction: Cu(OH)2 + 2H+ =Cu2+ +2H2O concentrated sulfuric acid and copper reaction:

Although concentrated sulfuric acid is also a strong electrolyte, it is not written as an ion because there is very little water) 2H2SO4 + Cu ==Cu2+ +SO42- +SO2 + 2H2O Special: Hou Debang alkali method: NaCl + NH3 + CO2 + H2O ==NaHCO3 +NH4ClNA+ +NH3 + CO2 + H2O ==NAHCO3 +NH4+ (although NaHCO3 is also a strong electrolyte, due to the low solubility in this reaction, it will precipitate, So not separated) finally the iron sheet is put into the ionic equation in dilute sulfuric acid:

fe + 2h+ =fe2+ +h2

In the ion equation, weak electrolytes, oxides and gases cannot be disassembled, such as weak acids such as water and acetic acid, weak bases such as ammonia monohydrate, iron oxide is a precipitate, and gases are molecular or atomic structures.

Introduction to the ion equationAn ionic equation, i.e., a formula that represents an ionic reaction with the symbol of the ions that actually participate in the reaction. Refers to the reaction in which soluble substances are detachable. The ionic equation not only represents a certain reaction between certain substances, but also represents the same type of ionic reaction.

For example, H++OH-=H2O can represent the neutralization of many strong acids and bases.

Whether a variety of ions can coexist in the same solution in large quantities can be summed up as: one color, two sexes, three special, and four reactions. To write an ionic equation, you must first determine whether the reaction is an ionic reaction or not.

For example, the reaction of acetic acid with sodium carbonate is an ionic reaction, and the reaction of acetic acid with ethanol to produce ethyl acetate and water is not an ionic reaction.