Chemical formulas and literal expressions and chemical expressions, please 3Q

NH4HCO3 Aerugino Cu2(OH)2CO3 HCl HCl"L" lowercase letters Potassium manganate K2MNO4 Manganese dioxide MNO2 (MG) Magnesium + oxygen (O2) - ignition Magnesium oxide (Mgo (P) red phosphorus + oxygen (O2) - ignition Phosphorus pentoxide (P2O5) Ammonium bicarbonate (NH4HCO3) - water (H2O) Carbon dioxide (CO2) Ammonia (NH3) Basic copper carbonate Cu(OH)2CO3--- water H2O CO2 Copper oxide Cuo KMNO4 Potassium permanganate -- Potassium manganate KMno4 Manganese Dioxide MnO2 Oxygen O2 Iron Fe Oxygen O2 – Ignition Ferric Tetroxide Fe3O4

1. 1 Ammonium bicarbonate NH4HCO3 2 Cu2(OH)2CO3 3 HCl HCl 4 potassium manganate K2MNO4 5 Manganese dioxide MNO2 6 liquid oxygen O2 3. Distinguish nitrogen, oxygen, air and carbon dioxide in the simplest way. 1. Use a small wooden strip that burns in the original form of the air, burns more vigorously with oxygen, extinguishes carbon dioxide or nitrogen, 2. Clarified lime water, becomes turbid with carbon dioxide, and there is no obvious phenomenon with nitrogen.

TextExpressionsIt is a tool for beginners in chemistry to know, understand, and familiarize themselves with various reactionsChemical equationsIt was very important to express the reaction to the style of the fierce town celebration. It is often encountered in the early stages of chemistry learningChemical reactions, in terms of what we have learned, there is nothing to say, so it is expressed in words.

For example, electrified water——— branch grip - hydrogen + oxygen.

1. Write the reaction conditions in the chemical equation. The general ones are marked with δ above the equal sign. Trim coefficients are mostly not fractions (except for reductions between them).

2. The reaction that can be carried out under normal temperature and normal pressure does not need to write conditions; However, if the experiment in the title has a specific condition, it is always marked with that specific condition (e.g., heating).

3. When reacting to a single condition, the condition is written above; If there are two or more conditions, what cannot be written above is written below; When there is both a catalyst and other reaction conditions, the catalyst is always written on it.

The chemical literal expression is: for example, the literal expression for sulfur combustion in oxygen is: sulfur + oxygen (the word "ignited" is written above) sulfur dioxide.

Properties of oxygen:

Magnesium burns in air: 2mg + O2 ignites 2mgo.

Iron burns in oxygen: 3Fe + 2O2 ignites Fe3O4.

Copper is heated in air: 2cu + o2 heats 2cuo.

Aluminum burns in air: 4Al + 3O2 ignites 2Al2O3.

Thermochemical equation:

The heating chemistry equation needs to indicate the state of each reactant and product, which can be divided into four categories: G (gas), L (liquid), S (solid), and AQ (solution). Letters need to be parenthesed, e.g. H2O (L), Na2CO3 (AQ), CaCO3 (S).

Ordinary equations do not use the g, l, s, and aq markers. In terms of products, when there is no gas in the reactants, the gas products should be marked with ""; Only in solution, when the reactants do not contain solids, insoluble or solid products are always marked with "".

Chinese. Literal expressions are expressions that use Chinese characters to express chemical search reactions and reaction conditions. Such as sulfur combustion: sulfur + oxygen dioxide pin leaks sulfur (write the word "ignite" above the arrow).

The chemical equation not only indicates the reactants, products, and reaction conditions. At the same time, the stoichiometric number represents the quantitative relationship between the reactants and the product substances, and the mass relationship between the substances can also be expressed through the relative molecular mass or relative atomic mass, that is, the mass ratio between the substances. For gas reactants and products, the volume ratio can also be obtained directly from the stoichiometric number.

In general, writing chemical expressions is to write text tables, symbolic expressions, and chemical equations as required.

For example, Shilushou:

The paper asks for the expression of the chemical formula, then write the chemical formula, not the chemical equation with the liter, and the formula that uses the element symbol to express the composition of the pure substance and the number of atoms is called the chemical formula. For example, the chemical formula of water is H2O, and calcium carbonate is CaCO3;

The chemical equation is an expression of a chemical reaction process, such as the thermal decomposition of calcium carbonate: CaCO3 heating = CaO+CO2

On the test paper, you should write the chemical expression, and change the name of the substance in the text expression to the chemical formula.

The chemical equation is not to be done carefully, but to write the chemical formula of the substance, but also to balance the number of atoms of each element on the left and right sides of the chemical equation equal sign. Xiang Fool Heng.

Chemical formula expressions, of course, are written as chemical formulas, not chemical equations. The definition of chemical formula is: The element tung branch and symbol are used to form a formula that implies the chemical composition of a substance. For example, water is H2O.

1.A chemical expression simply represents a chemical change, which can be written in Chinese characters, and the generation of volts can be represented by arrows. Example: sodium hydroxide + sulfur pure copper spine acid to do osmotic copper hydroxide (precipitation, blue) + sodium sulfate.

2.Chemical equations should be written in chemical formulas, balanced, and equal signs. Example: 2NaOH+CuSO4=Cu(OH)2 precipitation + Na2SO4 precipitation symbol) + Na2SO4

It is required to write a chemical expression, that is, to write the formula of the composition of substances with the symbols of chemical elements, not a chemical equation, for example, the chemical expression of hydrogen combustion to produce water is written as "h2+o2=h2o", the chemical expression does not need to be balanced, and the chemical expression is not a literary expression.

Chemical reactions, not equations. The equation is a formula in which the number of atoms on both sides is equal, and the reaction formula is the composition of each substance before and after the reaction. They are different.

The chemical table rents the Wooda formula and expresses the chemical equation in a simplified way. For example: Bad celebration or.

2NaHCO3 (Wet, hot) Na2CO3+CO2+H2O

The expression of the chemical formula of the slow attack of the effect of the nursing: 6CO2 + 6H2O C6H12O6 + 6O2, the top of the arrow is light, and the bottom of the arrow is chlorophyll (remember that it is definitely chlorophyll, the main chemical thing.

The disadvantages of chemical symbolic expressions are: Acacia panicle HE, neon gas NE, argon AR, krypton KR, xenon lead Bubu XE, radon RN, gold AU, silver AG, copper Cu, iron Fe, aluminum AL, calcium Ca, sodium Na, potassium K, carbon C, phosphorus P, sulfur S, silicon Si, boron B, arsenic AS, hydrogen H2, oxygen O2, nitrogen N2, fluorine F2, chlorine Cl2, bromine water BR2, iodine I2, carbon monoxide CO, carbon dioxide CO2...

Indicates the reaction of a substance and a substance. Definition: The word "chemistry" is "the science of change" if taken literally.

Chemistry, like physics, is the basic science of natural science. Chemistry is a natural science based on simple and simple experiments. A lot of people call chemistry the "central science," but that's a not-so-accurate concept.

It is the study of the composition, structure of matter.

Chemical element symbols are usually represented by the first letter (uppercase) of the Latin name of the element. If the first letter of several element names is the same, add another letter (must be lowercase) in the element name after the first letter (must be uppercase) to distinguish them.

What are the chemical symbolsGas HE, Neon NE, Argon AR, Krypton KR, Xenon XE, Radon RN, Gold Au, Silver AG, Copper Cu, Iron Fe, Aluminum AL, Calcium Ca, Sodium Na, Potassium K, Carbon C, Phosphorus P, Sulfur S, Silicon Si, Boron B, Arsenic AS, Hydrogen H2, Oxygen O2, Nitrogen N2, Fluorine F2, Chlorine Cl2, Bromine Water BR2, Iodine I2, Carbon Monoxide CO, Carbon Dioxide CO2, Sulfur Dioxide SO2, Sulfur Trioxide SO3.

What is a chemical symbolChemical symbols refer to the symbols used to represent various elements, all groups of substances except mixtures, and their atomic numbers in chemical and equilibrium science, and can be applied to various reaction formulas. The chemical symbol has undergone different evolutions in different regions, and finally in 1841, it was formed with a chemical symbol that has universal use in the world, and it is still used today.