What is the meaning of acid and base, what is the definition of acid and base?

Acid: A compound that can be ionized in an aqueous solution to produce hydronium ions H3+O. Alkali: A compound that can be ionized in an aqueous solution to produce hydroxide ion oh-.

Acid-base ionization theory.

The theory of acid-base ionization was proposed by Arrhenius, and the compound in which all the cations ionized in the aqueous solution are hydrogen ions is called acid, and the compounds that are ionized in the aqueous solution are all hydroxide ions are called bases.

Acid-base proton theory.

In order to make up for the shortcomings of Arrhenius's ionization theory, the Danish chemist Brunsti and the British chemist Laurie proposed the acid-base proton theory in 1923. The main points are as follows:

Everything that can give protons is an acid, and everything that can accept a proton is a base.

Acid-base conjugation: acid = base + proton (the stronger the acid, the weaker its conjugate base).

Definition of pH: pH = -LG [concentration of hydrogen ions] (proposed by the Danish physiologist Sorensen).

Under this theory, water is both acidic and alkaline.

Lewis acid-base theory.

Lewis gave a broader theory of acid-base, which states that anything that can accept electron pairs is an acid, and everything that can give an electron pair is a base. Boric acid can accept electrons on hydroxide in water and is acidic, which is a typical Lewis acid, and there are lone pairs of electrons on the ammonia molecule, which is a Lewis base.

Acid: Chemically refers to a compound in which the cations produced when ionized in an aqueous solution are all hydrogen ions. It can be divided into inorganic acids and organic acids.

Base refers to a substance that ionizes anions in an aqueous solution and is all OH-; In acid-base proton theory, a base refers to a substance that can accept protons; In acid-base electron theory, a base refers to an electron donor.

Salts refer to a class of compounds in which metal ions or ammonium ions (NH4+) are combined with acid ions or non-metal ions. Such as sodium chloride, calcium nitrate, ferrous sulfate and ammonium acetate calcium sulfate.

A solution is made up of at least two substances.

1. A stable mixture in which the dispersed substance (solute) is dispersed in molecules or smaller particles in another substance (solvent).

Acids: Acids are also acids in compounds that produce all cations (H+) when ionized, or substances that dissolve in water and release protons to form H3O+ (hydronium ions). Alkali:

In the theory of acid-base ionization, alkali refers to the compound that ionizes anions in aqueous solution, all of which are OH-; In acid-base proton theory, a base refers to a compound that can accept protons; In acid-base electron theory, a base refers to an electron donor.

1.According to organic and inorganic, it is divided into inorganic acids and organic acids.

Organic acids refer to some organic compounds that are acidic. The most common organic acids are carboxylic acids, which are acidic from a carboxyl group (-COOH). Sulfonic acid (-so H), etc., are also organic acids. Organic acids can react with alcohols to form esters.

2.According to whether it contains oxygen or not, it is divided into oxygenated acid and anaerobic acid.

Oxygenated acids (such as sulfuric acid HCO, carbonated HCO, etc.) and anaerobic acids (such as hydrochloric acid HCl, hydrofluoric acid HF, etc.).

3.Depending on the number of H+ that can be ionized from the acid molecule.

It can be divided into monobasic acid (HCl), dibasic acid (Hso), and tribasic acid (HPO)4According to the strength of acidity, acids are divided into strong acids, medium strong acids, weak acids (whether they can be completely ionized), strong acids (HCl, etc.), moderately strong acids (HPO, etc.), weak acids (HCOs, etc.)5According to whether it is a central atom or not, the electrons are divided into strong oxidizing acids and non-strongly oxidizing acids.

Strong oxidizing acids (HNO, etc.).

1.According to the number of hydroxide ions ionized by a base molecule: monobasic base, dibasic base, poly base;

2.According to solubility: soluble base; Slightly soluble bases; insoluble bases;

3.According to ionization capacity: strong base, weak base.

Acidity and alkalinity are the characteristics of substances in the acid-base reaction, generally speaking, the violent state of acidic substances can make purple litmus solution red, and alkaline substances can make it blue.

There are three scales of acidity and alkalinity: pH and POH of an aqueous solution, PKA of an acid and PKB of an alkali, and chemical hardness of an acid or base. Acidity and alkalinity are generally tested by pH test paper, litmus test solution, and phenolphthalein test solution.

Acids and bases. Acid (sometimes used"ha"The traditional definition is a compound that, when dissolved in water, has a greater concentration of hydrogen ions in solution than in pure water.

In other words, the pH of an acidic solution is less than the pH of water (25 is 7 for water). Acids generally have a sour taste, but tasting acids (especially in high concentrations) is very dangerous. Acids can be neutralized by silver sources and alkalis to produce water and salts.

Acids can be divided into two types: inorganic acids and organic acids.

Alkali refers to a class of substances as opposed to acids. Alkali mostly refers to the hydroxide of alkali metal and alkaline earth metal, usually refers to the bitter taste, the solution can change the color of a specific indicator substance (such as purple litmus blue, phenolphthalein red, etc.), the pH value of the aqueous solution is greater than 7.