Chemistry system nomenclature How is chemical system nomenclature named?

1: 2,6-dimethyl-3-ethylheptane.

2: 2,3,6-Trimethyl-5-ethylheptane.

3: 2,3,5-Trimethyl-4-ethylheptane.

4: 3,3,4,6-tetramethyl-6-ethyloctane.

5: 2,4,4-Trimethyl-3,3-diethylhexane.

6: 2-methylbutane.

7: 2,2-Dimethylpropane.

Very basic compound naming, see more and practice to make progress.

Write the carbon chain skeleton first, and then pick out the longest carbon chain, the weighted sum of the coefficients is as small as possible, and the higher the group weighted the greater (methyl group) ethyl group (that is, the position coefficient of methyl group is given priority).

Then let's practice more.

c-c-c-c-c-c-c

c c cc

2,6-Dimethyl-3-ethylheptane.

c-c-c-c-c-c-c

c c c c

C2,3,6-Trimethyl-5-ethylheptane.

c-c-c-c-c-c

c c c c

c c finishing, yes.

c-c-c-c-c-c-c

c c c c

C2,3,5-Trimethyl-4-ethylheptane.

c cc c

c-c-c-c-c-c-c

c c c collated with c c

c cc-c-c-c-c-c-c-c

C c C3,3,4,6-tetramethyl-6-ethyloctane. cc cc-c-c-c-c-c

c c cc

2,4,4-Trimethyl-3,3-diethylhexane.

c-c-c-c-c

C2-methylpentane.

cc-c-c

C2,2-dimethylpropane.

When there are multiple substituents on the main chain, the order of the groups in the name is determined by the order rule. The general rule is:

Compare the atomic number of the first atom of each branch chain and substituent attached to the main chain carbon atom (isotopes according to the relative atomic mass), and the larger atomic number is the "superior" group. The higher the ordinal number, the higher the order. Note:

In general, the larger the ordinal number, the greater the relative atomic mass. Therefore, the relative atomic mass can also be compared.

For example: i>br>cl>f>o>n>c

If the first atoms are the same, then compare the order of the atoms connected on their first atom; If there is a double or triple bond, it is considered that 2 or 3 identical atoms are connected.

The highest functional group is used as the main functional group, and the name is placed last. For other functional groups, the lower the order of naming, the higher the name.

For example: -ch2br>-ch3

If the first atom of these two groups is the same (both are c atoms), then compare the atoms attached to the c atom, which are br, h, h (in descending order of atomic number) and h, h, h, because br >h, so -ch2br>-ch3.

Selection of the main chain or main ring system

The longest carbon chain containing the main functional group is used as the main chain, and the end close to the functional group is marked as carbon No. 1.

If the core of a compound is a ring (system), then the ring system is considered to be the parent; With the exception of the benzene ring, each ring system determines carbon No. 1 according to its own rules, but at the same time ensures that the position number of the substituent is minimal.

One carbon atom in the branch chain that is connected to the main chain is marked carbon No. 1.

The basic steps of alkane naming are: select the main chain and write the carbon number, as follows: 1. Select the main chain:

Find one "long" and one "more", that is, the longest carbon chain and the most branches. Find out the longest carbon chain from the molecule as the backbone. If there are several carbon chains of equal length, the largest number of branches should be selected as the main chain. ch3-ch - ch-ch2-ch2-ch-ch3 ch3 c2h5 ch3 The longest carbon chain has 7 carbon atoms, so it is called heptane; 2. No. C:

Where there are several numbering possibilities, the substituents should be selected to minimize the position. For simple alkanes, the number starts from the nearest end of the branch, and the position and substituent nouns should be connected by a "—" line; 1 2 3 4 5 6 7 ch3-ch - ch-ch2-ch2-ch-ch3 ch3 c2h5 ch3 2,6 methyl group, 3 on ethyl 3, write name: the base name is the same, to be merged; Comma interval, ** points; Simplify first, then don't fight.

The same name of the substituent should be written together, separated by "," between different positions, and separated by "-" between Arabic numerals and Chinese characters; Substituents are written in the order of first simple and then complex. From this, the name of this alkane is: 2,6-dimethyl-3-ethylheptane, I hope my answer can be helpful to your learning!

Summary. Hello, it is my pleasure to answer the problem of systematic nomenclature and common nomenclature of chemistry: systematic nomenclature is a nomenclature developed according to the nomenclature of IUPAC and the characteristics of Chinese characters.

The common nomenclature is the most primitive nomenclature method according to the structure of the hydrocarbon group, which is the naming method for simple compounds and the naming of counterstaining compounds. The International Union of Pure and Applied Chemistry (IUPAC), also known as the International Union of Pure and Applied Chemistry, is a non-governmental organization dedicated to the promotion of chemistry, a joint organization of national chemical societies, and a member of the International Science Council. The organization is considered a recognized authority on chemical nomenclature, and the Subcommittee on Nomenclature and Symbolism annually revises the International Chemical Union nomenclature in an effort to provide accurate rules for the nomenclature of compounds.

In 1919, the International Union of Pure and Applied Chemistry was reorganized in Paris, France. In 1930, the International Union of Pure and Applied Chemistry was abbreviated as the International Union of Chemistry. In 1951, the full name of the International Union of Pure Applied Chemistry was restored.

Hello, it is my pleasure to answer the problem of systematic nomenclature and common nomenclature of chemistry: systematic nomenclature is a nomenclature developed according to the nomenclature of IUPAC and the characteristics of Chinese characters. The common nomenclature is the most primitive nomenclature method according to the structure of the hydrocarbon group, which is the naming method for simple compounds and the naming of counterstaining compounds.

The International Union of Pure and Applied Chemistry (IUPAC), also known as the International Union of Pure and Applied Chemistry, is a non-governmental organization dedicated to the promotion of chemistry, a joint organization of national societies for continental fissure, and a member of the International Science Council. The organization is considered a recognized authority on chemical nomenclature, and the Subcommittee on Nomenclature and Symbolism annually revises the International Chemical Union nomenclature in an effort to provide accurate rules for the nomenclature of chemical compounds. In 1919, the International Union of Pure and Applied Chemistry was reorganized in Paris, France.

In 1930, the International Union of Pure and Applied Chemistry was abbreviated as the International Union of Chemistry. In 1951, the full name of the International Union of Pure Applied Chemistry was restored.

Dear, is there anything else you need help with.

I'll drop that picture.

What is the system naming.

How to read this chemical equation. Right. ok

This is propylene.

In chemistry, in order to avoid confusion or misunderstanding, various chemical substances need to be systematically named to determine their chemical composition and structural formula. Generally, chemical nomenclature includes the following steps:

Determine the type and number of atoms in the molecule, expressed according to the element symbol and the Greek alphabet. For example, H for hydrogen, O for oxygen, N for nitrogen, C for carbon, etc.

According to the type and number of atoms in the molecule, its molecular formula is determined.

Determine the arrangement of the atoms in the molecule and construct the structural formula of the molecular formula.

According to the structural formula, the type and position of each functional group in the molecule are determined, and the molecule is named.

According to the chemical formula and chemical nomenclature convention, the systematic naming of compounds is constructed. In general, chemical nomenclature involves two main categories: organic and inorganic compounds.

When it comes to the nomenclature of organic compounds, it is usually done in the following order:

Determine the main chain and number the main chain.

Determine the type and location of the functional group, and prefix it accordingly before the main chain.

The position of the substituents is determined, and the corresponding prefix is added to the functional group.

According to the chemical formula and nomenclature rules, a systematic naming of organic compounds is constructed.

When it comes to the nomenclature of inorganic compounds, it is usually done in the following order:

Determine the chemical formula and name of the cation and anion.

If the cation has multiple valence states, the posture mode needs to be represented in Roman numerals.

If the anion is made up of multiple single negative ions, it needs to be represented by a prefix.

According to the chemical formula and nomenclature rules, the systematic naming of inorganic compounds is constructed.

In conclusion, in chemistry, systematic naming is very important to help people accurately understand the composition and structure of chemical substances, so as to better carry out chemical research and application.

The backbone is selected first, so that the branch chain attached to the carbon atom of the backbone is a complete substituent. The ethyl group is a group of hydrogen atoms removed from the ethane molecule, which of course contains a methyl group, but the methyl group cannot exist independently, so the entire branch chain is called an ethyl group. See**.

The naming rule is that the longest carbon chain is the main chain, and the other branches are the branches.

Although there is a methyl group on the left head of the first one, it cannot be regarded as a branched chain, but a part of the main chain, with a total of 5 carbons, and the ethyl group is a branched chain, so it is named 3-ethylpentane.

In fact, this structure is a symmetrical structure, extending from the carbon in the middle in three directions, no matter how you count, the longest chain is 5 carbons, and the branch chain is two carbon ethyl groups.

Hope it helps.

1.First of all, your question is wrong.

The system nomenclature first determines the number of c atoms in the backbone.

Generally, the main chain is with more C atoms.

Like what. ch3-ch-ch3

CH3 here c has 4 on the main chain.

Generally, one is called A. The two are called already. Press A, B, C, D, Pentoxin, hexaxin, nondecane.

For example, the above is propane.

CH3 is a methyl group.

Because he is ch4 and has less H, since C only has 4 bonds at most. C2H5 is ethyl. And so on.

3.The position of the group is marked according to its smallest number on the main chain.

As above. 2--Methylpropane.

There are also such as: ch3-ch-ch-ch3

ch3ch3

There are two methyl groups, and the position of the two methyl groups is exactly what I marked in the number.

Then this is bi-2,4 methylbutan.

Generally, it is not expressed in ethyl.

A few are used. Hope you understand.

The three steps of systematic nomenclature, let's take a good look at the detailed description in the textbook.

What you are talking about by the name of this substance.

3,5-Dimethyl-3-ethylheptane.

The main chain has 7 C's, and the parent body is called.

Heptane, should be numbered from the left, because there is a finger methyl group on the third C on the left and right, and there is an ethyl group on the third C on the left, it should be numbered from the left, and when equidistant, look at the branched chains).

Take alkanes, for example:

1. Select the main chain and call a certain alkane (pay attention to the principle of the longest and the principle of the most branches).

c, e.g. c-c-c-c-c

The longest chain is the chain with the most Cs, and there are 5 C's, so choose this as the main chain.

I won't draw h) cc

Elephant. c-c-c-c

Which one do you think has the most C, that is, the main chain? It should be the L-shaped one, and if you choose the right one, it proves that you have understood"The longest principle"Finish. cc

c-c-cc

The most branched chains, such as c-c-c-c-c-c-c-c-c-c-c-c-c

Starting from the far left, up and like the right are the longest chains, right? But there are 2 branches up and 1 branch chain to the right.

2. Select the starting point (the nearest principle: the closest to the branch chain), the number of numbers (the minimum Zheng Xiang sedan chair principle: the smallest sum of the branch chain), and the fixed branch chain (the simplest principle: the simplest branch chain).

3. Writing rules: before the branch name, after the main name.

The name of the branch is the same, and it should be merged.

The names of the branches are different, and Jane is in front.

If it is a derivative, the main chain should start from the substituent, and there are some other substances whose naming methods are not easy to explain, and if you do the question, you will give a hint.

2,4,5-Trimethyl-4-ethylheptane is being argued.

3,4,5-trimethylhail heptane.

3,4,6-Trimethyl-4-ethyloctane.

3,4,5-Trimethylheptane.

The basic steps of alkane naming are: select the main chain and write the carbon number, as follows:

1. Select the main chain: find one "long" and one "more", that is, the carbon chain is the longest and the branch chain is the most. Find out the longest carbon chain from the molecule as the backbone. If there are several carbon chains of equal length, the largest number of branches should be selected as the main chain.

ch3-ch - ch-ch2-ch2-ch-ch3

ch3 c2h5 ch3

The longest carbon chain has 7 carbon atoms, so it is called heptane;

2. Numbered C: When there are several possible numberings, the position of the substituent should be selected to be the smallest. For simple alkanes, the number starts from the nearest end of the branch, and the position and substituent nouns should be connected by a "—" line;

ch3-ch - ch-ch2-ch2-ch-ch3

ch3 c2h5 ch3

There is a methyl group on 2,6 and an ethyl group on 3.

3. Write the name: the base name is the same, and it should be merged; Comma interval, ** points; Simplify first, then don't fight. The same name of the substituent should be written together, separated by "," between different positions, and separated by "-" between Arabic numerals and Chinese characters; Substituents are written in the order of first simple and then complex.

From this, the name of this alkane is:

2,6-Dimethyl-3-ethylheptane.