The general properties of acids and alkalis are to be written in equations , simplified

Acids do not react with all salts.

The general properties of acid-base salts are as follows:

Acids: Metals react with acids; reacts with acid-base indicators; and basic oxides; and alkali reaction and salt reaction; Bases: and indicators, reacts with acids, and acidic oxides, and salts; Salts: acids, alkalis, salts and alkaline oxides.

Acidic universality

The acid solution can react with the acid-base indicator, acid + alkaline oxide = salt + water, etc. Universality of alkali: the alkali solution can react with the acid-base indicator, the purple litmus test solution turns blue when it encounters alkali, and the colorless phenolphthalein test solution turns red when it encounters alkali. Insoluble alkali, such as can not make the acid-base indicator change, etc.

2. The universality of salt

Some salts are weakly corrosive, and the pH of the solution is determined by the nature of the salt, and it can react with certain acids, bases, salts, and other compounds. Acid is corrosive, the solution is acidic, can react with active metals, alkalis, some salts and metal oxides react with active metals discharged before hydrogen to form salts and hydrogen, and react with indicators, pH acidic solutions are not necessarily acids, but acids must be acidic solutions.

Alkali is corrosive. The solution is alkaline and can react with acids, certain salts, non-metal oxides, some bases can react with some metal oxides, and react with indicators The alkaline solution is not necessarily a base, but the alkali must be an alkaline solution. (Apparently alkaline solutions are not necessarily alkaline solutions, the so-called alkaline; But alkali must be alkaline, that is, the pH value is greater than 7.

Acid refers to compounds in which all cations produced during ionization are radon ions; Base refers to a compound in which all the anions produced during ionization are hydroxide ions; Salts refer to compounds that form metal cations (or ammonium ions) and acid ions when ionized. It can be abbreviated as: radon acid, oxygen, alkali, stove filial metal, acid, and salt.

Compounds formed only by the combination of oxygen ions and acid ions, and non-metallic elemental recesses are acids. The compound formed by the combination of metal ions and radon oxide ions is a base. Compounds formed by the combination of metal ions and acid ions are salts, not always of which is the case.

Examples such as Cu2(OH)2CO3 basic copper carbonate have hydroxide radicals. Acid-base salts must contain non-metallic elements.

Acids are universal: Acid + Acid-Base Indicator Acid + Metal --- Salt + Hydrogen Acid + Metal Oxide - Salt + Water Acid + Base --- Salt + Water Acid + Salt --- New Acid + New Salt.

General properties of alkali alkali + acid-base indicator alkali + non-metallic oxide alkali + acid --- salt + water alkali + salt --- neoalkali + new salt.

Salt has no common properties Chemical properties of salt Salt + metal --- new salt + new metal Salt + acid --- new salt + new acid salt + alkali --- new salt + new alkali.

Salt + Salt --- two new salts.

Acidic universality(1) The acid solution can react with the acid-base indicator.

2) Acid + Active Metal = Salt + Hydrogen.

3) Acid + Basic Oxide = Salt + Water.

4) Acid + Alkali = Salt + Water.

5) Acid + salt = new salt + new acid.

General properties of bases. (1) The alkali solution can react with the acid-base indicator, the purple litmus test solution turns blue when exposed to alkali, and the colorless phenolphthalein test solution turns red when exposed to alkali. Insoluble bases, such as not discoloring the acid-base indicator.

2) Alkali can react with acidic oxides to form salts and water.

3) Alkali can neutralize with acid to form salt and water.

4) The alkali can react with certain salts to form new alkali and new salt.

Universality of salt. 1 Metal (more active than metal in salt) + salt (soluble in water) – new metal + new salt.

2 Acid + salt - new acid + new salt (condition: the product has a weak electrolyte, gas or precipitate) 3 salt + salt - two new salts (condition: the reactants are soluble in water, and the product must have precipitation) 4 alkali + salt - new alkali + new salt (condition is the same as 3).

The general properties are as follows: Acid:

1: Metal sum calculation.

2: React with acid-base indicator.

3: and basic oxides.

4: Reaction with alkali and salt.

Base: 1: and indicator.

2: Reaction with acid.

3. Reaction with acidic oxides.

4. Reaction with salt.

Salt: reacts with certain acids and bases and salts and basic oxides.

Acid refers to compounds in which all cations produced during ionization are hydrogen ions; Base refers to a compound in which all the anions produced during ionization are hydroxide ions; Salts refer to compounds that form metal cations (or ammonium ions) and acid ions when ionized. It can be abbreviated as: hydrogen head acid, hydroxide end alkali, metal start acid end is salt.

Sour. Corrosive, the solution is acidic, can react with active metals, alkalis, certain salts and metal oxides react with active metals discharged before hydrogen to form salts and hydrogen, and react with indicators. A pH-sensitive solution is not necessarily an acid, but an acid must be an acidic solution (i.e., acidic).

Alkali. Corrosive. The solution is alkaline and can react with acids, certain salts, non-metal oxides, some bases can react with some metal oxides, and react with indicators The alkaline solution is not necessarily a base, but the alkali must be an alkaline solution.

(Apparently alkaline solutions are not necessarily alkaline solutions, the so-called alkaline; But alkali must be alkaline, that is, the pH value is greater than 7. ）

Salt. Some salts are weakly corrosive, and the pH of the solution is judged according to the nature of the salt, and it can react with certain acids, alkalis, and salts.

It can also react with certain other compounds.

Chloride ions: silver salts (except silver chloride).

Sulfate ions: barium salts (except barium sulfate).

Ammonium ion: base (optional).

Hydroxide ion: ammonium (NH+).

Hydrogen ions: carbonate and clarified lime water alkali.

Carbonate ions: acids (except carbonic acid), calcium salts, barium salts (except calcium carbonate and barium carbonate).

Iron ions: 2-valent iron ions are light green, 3-valent is yellow (refers to the solution, this knowledge only applies to secondary school).

Note: The Fe(OH)3 solution is reddish-brown. (Fe(OH)2 has no solution, the substance is a white precipitate.) ）

When encountering O2, it will quickly oxidize to gray-green, and eventually turn reddish-brown!

Copper ions: 2-valent copper ions are blue (refers to solution) (anhydrous copper sulfate is white).

Therefore, cao is a basic oxide.

Acid: The cations formed during ionization are all compounds with circular hydrogen ions, such as: HCl==H+ +Cl-

hno3==h+ +no3-

h2so4==2h+ +so42-

Base: A compound in which all anions are hydroxide ions are formed during ionization, such as: koh==k+ +oh-

naoh==na+ +oh -

ba(oh)2==ba2+ +2oh -

Salt: Compounds that generate metal ions and acids in the cavity state of ionization from simple sources, such as: kno3==k+ +no3-

na2so4==2na+ +so42-

bacl2==ba2+ +2cl -

1. Acid: reaction with alkali (acid-base neutralization reaction), such as HCL and Peiqiao Li NaOH reaction with basic oxides, such as HCL and CAO

Reacts with reactive metals (displacement reactions), e.g. HCL with Fe (see Metal Activity Order Table for reactive metals).

Reaction with weak salts (i.e., some salts) (follow the principle of late follow: strong acid to weak acid, high boiling point acid to volatile acid), such as HCL and CaCO3, HCL and Fes (special case: Cus, Cus insoluble acid, that is, not to react with acid), but also for example, sulfuric acid and NaCl (Kuanliang This reaction is volatile acid from high boiling point acid, which produces HCl gas, and from the perspective of ionic reaction, it is to generate HCl gas, so that its concentration decreases, and the reaction occurs.

This reaction is generally not taken in the high school entrance examination).

The litmus turns red, and the phenolphthalein is colorless.

2. Alkali. Reactions with acids (acid-base neutralization reactions), e.g. NaOH with HCl with acidic oxides, e.g. NaOH with CO2

Reacts with weakly alkaline salts (i.e., certain salts) (metathesis reactions), such as NaOH and CuCl2 (the law is the formation of insoluble bases, i.e., precipitates).

The litmus turns blue, and the phenolphthalein turns red.

Let's compare it.