High school chemical alkanes, how to name them, and high school chemical organics

1. Select the main chain: select the continuous longest carbon chain containing the most substituents as the main chain, as the parent alkane, and name an alkane according to the number of carbon atoms contained in the main chain.

2. Numbering: If there is a substitute, it will be numbered from one end close to the substituent, and the carbon atoms on the main chain will be numbered in turnmark their rank; When two different substituents are in the same position, the smaller subsituents in the order rule have a smaller number. When two identical substituents are at the same position, the third substituent should be as small as possible.

3. Naming: The backbone is the parent compound, if there are multiple identical substituents, the subsubstitutes are merged, and the substituents are used before the name of the substituent.

Two, three, four, etc. indicate the number of substituents.

If it is a normal alkane, it is named after the heavenly stem and there are several C's corresponding (A, B, C, D......When there are more than 10 c, use Arabic numerals, such as 11 alkane, etc.

If it is an isomer, use the systematic nomenclature.

1.Find the main chain (the straight chain with the most C), find the group outside the main chain, and the closer to the group on the main chain, the smaller the Arabic numeral of the C marker.

Such as ch3-ch2-chch3-ch3 named 2, methylbutane.

1 The 10 carbon atoms are called A, B, C, D, Pentohexylheptaxin, and the number of carbon atoms greater than 10 is named after the number, such as: 11 ane, 12 ane, etc.

Within 10 carbons of a single bond, methyl, ethylpropionate, butylpentylhexylheptaxin, nondecane, alkane. Ring-shaped reading: Ring, methyl, ethyl, propyl, butylpentyl, hexylheptane, nondecane, alkane. The chain-like double bond is an olefin.

The triple bonded ones are alkynes.

Use customary nomenclature. Within 10 carbons, A, B, C, D, pente, hexylheptane, nondecane + alkane. More than ten capital numbers + alkane. One branched chain reads isoalkane, and two branched chains read new alkane. Cyclic reading cycloalkane.

The customary nomenclature of alkanes: the number of carbon atoms in the molecule is followed by the word "alkane", which is the name of the simple alkane, and the representation of carbon atoms: Yu Yan.

The carbon atom is between 1 and 10, with the "heavenly stem";

If it is more than 10, it will be replaced by the Chinese character "eleven."

Twelve、......Denote.

Steps for the nomenclature of an alkane system.

Choose the main chain. a.The main chain should be long: choose the main carbon chain with a large number of carbon atoms.

b.There should be more branches: when the number of carbon atoms in the two chains is the same, it is good to let go, and the main carbon chain with more branches.

Common nomenclature 1. Alkanes are usually referred to as "certain alkanes", which refers to the number of carbon atoms in alkanes. From one to ten, it is represented by A, B, C, D, E, G, XIN, NON, and 癸, and from 11 to 10 is represented by Chinese characters.

The former, i.e., 2,9,12-trimethyl-7-ethyltetradecane.

Numbering should start at the end closest to the substituent.

The rules of systematic nomenclature of alkanes are as follows:

1) Directly connected alkanes are named according to the number of carbon atoms, the number of carbon atoms is within ten, and the number of carbon atoms is represented by Tiangan (A, B, C, D, hexylheptenctoxin, and nondean) in turn, and when it is above ten, Chinese numbers such as ten are directly used.

I. Twelve··· to indicate the number of carbon atoms.

2) Branched alkanes – Branched alkanes are named because they are alkyl derivatives of direct-linked alkanes.

a. Select the main train - the longest continuous carbon chain in the structural formula - as the parent is called a certain alkane. The shorter chain in the structural formula is regarded as a branch chain and is regarded as a substituent. When naming, the base name is placed in front of the parent name, which is called a certain base and a certain alkane.

If there is more than one long carbon chain in the middle of the structure, the one with the most substituents is selected as the main chain. When choosing a master, it should be noted that not only the written direct connection should be regarded as the main chain, but all continuously connected carbon atoms should be included in a carbon chain.

b. Starting from the end closest to the substituent, the carbon atom of the main chain is used with Arabic numerals 1,2,3, ·· Numbering.

c. When naming substituents, use their position on the parent chain as a prefix for the substituents. If there are several different substituents, the simple group name should be placed in front and the complex group name should be placed at the end (the English name should be named with the initial letters a, b, c, ·· in order). If there are several identical substituents, they can be combined, but the position and number should be written before the group name, and the number should be in Chinese characters.

II, III... to represent. For the sake of clarity, when writing the compound name, it should be noted that the digit positions should be separated by commas, the positions should be separated by **"-", and the last base name should be directly connected to the parent name.

3,6,13-Dimethyl-8-ethyltetradecane.

This is obviously wrong, it should be trimethyl.

I didn't see your addition, and the above was written and not removed.

Now let me talk about your question, 3,6,13-dimethyl-8-ethyltetradecane, this is not right, you must first rank the methyl group as the smallest, start, I hope you also choose me for this answer.

iii) Sequential Rules.

The various groups in organic compounds can be arranged according to a certain rule, which is called the order rule, and its main contents are as follows:

The monoatomic substituents are arranged according to the atomic number size, with the order of the large atomic number first, and the order of the small atomic number last, and the common order of elements in organic compounds is as follows:

i＞br＞cl＞s＞p＞f＞o＞n＞c＞d＞h

Among the isotopes, the order of the highest mass comes first.

If the first atom of two polyatomic groups is the same, the other atoms connected to it are compared, and when compared, they are arranged by atomic number, first comparing the largest, which is still the same, and then comparing the middle and smallest in order. Such as ch

2Cl with CHF

2, the first one is a carbon atom, and then the other atoms attached to the carbon are compared in order, in ch

C(Cl,H,H) in 2Cl and CHF

2 is c(f,f,h), cl is more than f first, h

2cl in front. If some of the groups are still the same, compare them one by one along the substitution chain.

A group containing a double or triple bond can be considered to have two or three identical atoms in a group, e.g. the following groups are arranged in the following order:

If the atoms participating in the comparison order have less than 4 bonds, an appropriate amount of imaginary atoms with zero atomic number can be added, and the order of the imaginary atoms is placed last. For example: ch3ch

In 2NHCH3, there are only three groups on N, then its fourth group is an imaginary atom with atomic number 0, and the order of the four groups is: CH3CH

2 ch3 h imaginary atom.

The first step in the nomenclature of the alkane system is to find the longest chain composed of carbon atoms, and after finding out, the remaining carbon atoms that are not included in the longest chain are all branched chains, which are "substituents". The number starts from one end of the longest chain, the number is the number on the carbon atom of the longest chain, and the number of the substitute, that is, the branch chain, refers to the position of the hydrogen atom on the main chain that it replaces, and its number is the number of the main chain of this carbon atom. In order to ensure that the sum of the branch numbers is minimized, it is necessary to select the carbon atom from the nearest end of the main chain to the substituent, which is 1, 2, 3, 4 ......, and then the substituents are sorted from simple to complex (from simple to complex are methyl, ethyl, propyl, ......These are all straight-chain n-alkyl groups, and there will be no more branched isoalkyl groups, which are only required by high school).

The following diagram is clearer:

The nomenclature of the alkane system: "Select the main chain, call a certain alkane, number bit, definite branched chain, substituent, write in front, position, name ** connection, different bases, simple to complex, the same base, combined." (This sentence is not original, and the numbers are roughly the same).

First of all, if you look from right to left, if you look at the carbon of the ethyl group, if you continue to the left, it is the longest carbon chain you said, but if you look down, there is also a carbon chain with six carbons. But naming it this way doesn't conform to the nomenclature convention, because branching is not the simplest. Then it can only be named 2-methyl-3-ethylhexane.

The second methyl group you mentioned did not show it, but it has already been manifested, and the ethyl group is CH3-CH2-, which contains a methyl group. This methyl group is not directly attached to the longest carbon chain, so it cannot be written.

If it's named like you, then there's one more methyl group on the third carbon.

If you name the system, you have to find the longest carbon chain and then mark it, otherwise you will be misnamed!!

2,9,12-Trimethyl-7-ethyltetradecane is right.

The backbone carbon atoms should be numbered, starting at the end closest to the simple substituent.

The nomenclature of 2,9,12-trimethyl-7-ethyltetradecane is correct. Because in the "systematic nomenclature" of organic matter, in the label order, which end branches first and which end is the first, that is, it is numbered 1.

The general formula of alkanes is CNH2N+2

then 12n+2n+2=100 n=7

So the molecular formula is C7H16

The main chain c-c-c-c-c has two C's left (1 2 3 4 5 for the carbon chain from left to right).

Two C's can be 1 2 or 1 3 or 2 3 or 2 2 or 3 3 so there are 5 kinds.

According to the general formula of alkanes, CNH2N+2, it can be seen that the alkane molecular formula C7H16 has 5 kinds of carbon on the main chain.

ch3ch(ch3)ch(ch3)ch2ch3ch3ch(ch3)ch2ch(ch3)ch3ch3c(ch3)2ch2ch2ch3

ch3ch2c(ch3)2ch2ch3

ch3ch2ch(c2h5)ch2ch3

2,2-Dimethylpentane CH3C (CH3), 2CH2CH2CH33,3-Dimethylpentane CH3CH2C (CH3), 2CH2CH32,4-Dimethylpentane CH3CH(CH3), CH2CH(CH3), CH32,3-Dimethylpentane, CH3CH(CH3), CH(CH3), CH2CH33-ethylpentane, CH3CH2CH2CH(C2H5), CH2CH3

Molecular formula: C7H15

Remove the two cc-c-c-c-c-c

Placed in an arrangement: there are 3 on the same carbon

Different: 36 species.

In this topic, you first have to determine the molecular formula according to the relative molecular mass, and the alkane is determined to be C7H16, and the last thing you need to do is to draw the isomers of 5 carbons on its main chain, draw a chain of 5 carbon atoms, and then add substituents on it, which is very easy to calculate. If it's good, there should be 6 types.

There are 5 kinds, let the molecular formula of alkanes be CNH2N+2, then 14N+2=100, so the molecular formula of alkanes is C7H16, so there are five isomers.

There are a total of 9 isomers, and there are 5 isomers with 5 carbon atoms on the backbone.

1，c4h10。The weight gain of concentrated sulfuric acid is the mass of water, and the amount of water substance can be known, so the amount of H atomic substance is 1mol. The weight gain of concentrated alkali is the mass of CO2, and the amount of carbon dioxide is that because it is a certain hydrocarbon, 1mol hydrocarbon can be obtained with 10molH atoms and 4molc atoms, that is, the hydrocarbon is C4H10.

2，c3h8。Basically the same as the first one, from the ratio of water and carbon dioxide, we can get c:h=:8, that is, c3h8. Verifiable according to conditions.

1) Common nomenclature.

1. Alkanes are usually referred to as "alkanes", which refers to the number of carbon atoms in alkanes. From one to ten, it is represented by A, B, C, D, E, G, G, XIN, NON, and 癸, and since eleven is represented by Chinese character numbers.

1) CH4 is called methane, CH3CH3 is called ethane, CH3CH2CH3 is called propane;

2) C15H30 is called pentadecane.

2. In order to distinguish isomers, they are represented by "positive", "heterogeneous" and "new".

The common nomenclature is simple and convenient. But it can only be used.

Alkanes with relatively simple structures. For alkanes with complex structures, systematic nomenclature must be used.

In the systematic nomenclature, branched alkanes are considered as alkyl substituent derivatives of linear alkanes.

Therefore, the nomenclature of branched alkanes can be carried out according to the following steps:

1. Select the main chain.

From the structural formula of alkanes, select a carbon chain with the largest number of carbon atoms as the backbone, and write the name of the straight-chain alkane equivalent to this backbone.

ch3 — ch — ch2 — ch2— ch2 — ch3

The carbon chain in the middle line of the above equation is the longest, and as the parent body, it contains six carbon atoms, so it is called hexane. The methyl group is used as a substituent.

2. The position number of the carbon atom of the main chain.

After selecting the main chain, it is necessary to carry out the position numbering of the main chain, that is, to determine the position of the substituent, the main chain is numbered from one end to the other, the number is represented by 1, 2, 3, etc., read as 1 bit, 2 bits, 3 bits, etc.

The principles for determining the position of the main chain are:

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 "—" half-word line.

ch3 — ch 2— ch — ch2— ch2 — ch3

ch3ch3 — ch 2— ch — ch2— ch2 — ch3

CH3 is: 3-methylhexane.

Read: 3 methylhexane.

Methyl "Ethyl" "Propyl" "Butyl" "Amyl" "Hexyl" "Isoamyl" Isobutyl "Isopropyl".

4. When a chain with the same length can be used as the main chain, the carbon chain with the largest number of branches should be selected.

Have a nice day.