How to write the chemical structural formula, how to write the structural formula of a substance in

Writing of elemental chemical formulas.

1.with element symbols.

Representation: 1) All metals. Chemical formulas such as etc.

2) All noble gases.

Such as, etc. 3) Non-metallic elemental substances in the solid state. Such as S, P, C, etc.

2.Diatomic molecules:

1) Non-metallic elements in liquid form. Such as, etc.

2) Gaseous non-metallic elements (except for rare gas elements). Such as, etc.

Description: The vast majority of elemental elements are written in the above rules, but there are some special, such as ozone, as a gaseous non-metallic element, its chemical formula is; Iodine is a solid non-metallic element at room temperature, and its chemical formula is.

Two. Writing of chemical formulas of chemical compounds.

For the writing of chemical formulas of compounds, we can divide it into three steps:

determine the constituent elements of a substance according to its name;

Write out the symbols of each element in order according to the arrangement rules;

Identify and indicate the number in the lower right corner of each element's symbol.

Learned valence.

It will be easier to write some complex chemical formulas.

Then in the chemical formula, the order in which the symbols of the elements are arranged is:

1) If it is made of metallic elements.

Composed of non-metallic elements, generally metallic elements are written on the left and non-metallic elements are written on the right. Such as, etc.

2) If it is made of oxygen.

With other elements, generally the other elements are written on the left, and the oxygen element is written on the right. Such as, etc.

3) If it is made of hydrogen.

Composed of other non-metallic elements, generally hydrogen is written on the left, and other non-metallic elements are written on the right (except NH3, CH4, etc.). Such as HCL, H2O, H2S, etc.

4) If it is composed of three elements, the general order is "metal left oxygen right non-metal middle" or "hydrogen left oxygen right non-metal middle". Such as H2SO4, Na2CO3, KNO3, etc.

Elemental: Except for rare gases with gas prefixes, "2" is added to the lower right corner of the element symbol, and the rest of the elemental substances (containing rare gases) are directly represented by element symbols except bromine and iodine.

Compounds: One row.

Discharge element symbols or clusters of atoms (positive first, negative last.) Methane removal.

ammonia) two standards.

The valency is marked directly above the element symbol or atomic cluster.

3. If the sum of positive and negative prices is not 0, the cross number is marked as a footmark (the number in the lower right corner) "1" is not written.

Fourth, the whole inspection of inorganic substances.

The offer point (number in the lower right corner) that can be reduced

Reactant on the left, product on the right.

Write the chemical formula well, and the equation should be balanced.

**Change the equal sign, the conditions should be indicated.

Generate gas or precipitate, up and down arrows to distinguish.

Emphasis is placed on writing chemical equations.

The key and difficult point is the trimming of the equation and attention should be paid to its normalization.

How to Write Chemical Equations.

The same molecular formula may have different structures, just pay attention to all the atoms to reach a stable structure when writing.

For example, butane (C4H10) has two structural formulas:

h h h h

h-c-c-c-c-h

h h h h

h h hh-c-c-c-h

h-c-h Note: Don't write when you write ).

In fact, the most commonly used is the structural short-form, that is, there is no -.

For example, the first one can be written as ch3ch2ch2ch3, and the second one can be written.

ch3ch（ch3）ch3

If it is a common two electron pairs, it is represented by =, such as o=c=o(CO2), and the double bond must be written when writing the structure short, and the triple bond is the same.

Here are some of the atoms or functional groups that are often seen in high school:

c-、h-、br-,cl-,o=,ho-,o=ch-、c-o-c、c=c,c≡c

cooh,coo-,c=o

I didn't expect it to be so messy after playing for so long, if you can understand it, just watch it. If you don't understand, try to ask the teacher

First, write out the elemental symbols that make up the elementThen write the number of atoms that make up a single molecule in the lower right corner of the element symbol with a number.

Noble gases are directly composed of atoms and are usually represented by elemental symbols for their chemical formulas.

The structure of metal elemental and solid non-metallic elemental knots is more complex, and it is customary to use element symbols to express their chemical formulas. The writing rule of compounds is to first write out the symbols of all the elements that make up the compound in the order of positive, first and negative, and then write the number of atoms of that element in each compound molecule with a number in the lower right corner of each element symbol.

A certain order usually refers to: a compound composed of oxygen and another element, and the oxygen symbol is generally written on the right; Hydrogen and another element form a compound that forms a ridge, and the hydrogen symbol is generally written on the left; For compounds composed of metallic elements, hydrogen elements and non-metallic elements, the non-metallic element symbol should generally be written on the right. The chemical formula of a compound that is directly composed of ions is often expressed as the simplest integer ratio of its ions.

Carbon dioxide: CO2 sodium chloride: NaCl

Sodium carbonate. na2o

3 sulfuric acid: H2SO4

Carbon monoxide: CO

Chloride sub-disturbance Qiaochang iron.

FeCl2 calcium carbonate:

CaCO3 hydrochloride: HCl

Phosphorus pentoxide.

P2O5 aluminum chloride.

Alcl3 barium carbonate.

BaCO3 oxygen: O2

Ferric oxide.

Fe2O3 calcium chloride.

CaCl3 potassium carbonate.

K2CO3 nitrogen:N2

Calcium oxide. cao

Potassium chloride. kcl

Silver nitrate. AG2CO3 hydrogen:H2

Alumina: Al2O3

Ferric chloride. fecl3

Methyl iron nitrate.

fe(no3

2 chlorine: cl2

Copper oxide. cuo

Potassium sulfate. kno3

Magnesium nitrate. mg(no3)2

Zinc oxide. zno

Manganese dioxide. mno

Zinc sulfate. zaso4

Sodium hydroxide. naoh

Mercuric oxide. hgo

Sulfur dioxide. so2

Iron sulfate. fe2(so4)3

Calcium hydroxide. ca(oh)2

Magnesium oxide. mgo

Baryta. bao

Copper sulphate. cuso4

Aluminum hydroxide. al(oh)3

Ferrous oxide. feo

Sodium oxide Na2O

Barium sulfate. baso4

Magnesium hydroxide.

mg(oh)2

Silver chloride. agcl

Hydrogen peroxide H2O2

Ferrous sulfate FeSO4

Copper hydroxide. cu(oh)2

Barium chloride. bacl2

Water H2O potassium manganate.

k2mno4

Potassium permanganate. kmno4

Copper chloride. cucl2

Iron oxide. fe2o3

Potassium chlorate. kclo3

Ammonium sulphate. nh4)2so4

Calcium sulphate. caso4

Sodium sulfate. na2so4

Aluminum sulfate. al2(so4)3

Magnesium sulfate. mgso4

Silicon dioxide. sio2

Hydrogen fluoride. hf

Barium hydroxide. ba(oh)2

Iron hydroxide. fe(oh)3

Zinc hydroxide. zn(oh)2

Ferrous hydroxide.

fe(oh)2

Potassium hydroxide. koh

Barium nitrate. ba(no3)2

Ferric nitrate. fe(no3)3

Copper nitrate. cu(no3)2

Ammonium nitrate. nh4no3

Potassium nitrate. KNO3 potassium permanganate KMNO4

Zinc sulfide. zns

For the sake of my hard work, I should have given me the score.

Elemental, oxide, acid, alkali, salt chemical formula writing detailed Ling crack book macro introduction. Source Wang.