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Calculate Index of Hydrogen Deficiency in Chemical Engineering
On the Calculation of Hydrogen Deficiency Index
In the field of chemical industry, the calculation of the Index of Hydrogen Deficiency (IHD) is quite important in order to understand the wonders of material structure. It can show the degree of molecular unsaturation and the clue of the analytical structure.
1. The principle of hydrogen deficiency index
The hydrogen deficiency index is to compare the studied molecule with the saturated chain hydrocarbon containing the same number of carbons to observe the difference in the number of hydrogen atoms. The general formula for saturated chain hydrocarbons is $C_nH_ {2n + 2} $. If the number of carbon in a molecule is $C $, the number of hydrogen is $H $, the number of halogen atoms is $X $, and the number of nitrogen atoms is $N $, then the hydrogen deficiency index is calculated as follows:
\ [IHD =\ frac {2C + 2 + N - H - X} {2}\]
The source of this formula is that every degree of unsaturation, or a double bond, or a ring, decreases the number of hydrogen atoms by two. The halogen atom has the same number of bonds as the hydrogen atom, so it can be regarded as hydrogen. The nitrogen atom forms a triple bond, and the introduction of a nitrogen atom is equivalent to adding a hydrogen atom.
Second, the calculation example shows
Example 1: Simple hydrocarbon
has a hydrocarbon molecule with the chemical formula $C_6H_ {10} $. Calculate its hydrogen deficiency index according to the above formula:
\ [IHD =\ frac {2\ times6 + 2 - 10} {2} =\ frac {12 + 2 - 10} {2} = 2\]
This shows that the molecule has two unsaturation degrees, or has a double double bond, or has a ring plus a double bond, or has two rings and other structures.
Example 2: If there is a halogen-containing nitrogen compound
, the chemical formula is $C_4H_7ClN $. Calculate its hydrogen deficiency index:
\ [IHD =\ frac {2\ times4 + 2 + 1 - 7 - 1} {2} =\ frac {8 + 2 + 1 - 7 - 1} {2} = 1.5\]
However, the hydrogen deficiency index must be an integer. Due to the complexity of the bonding of nitrogen atoms, the actual calculation requires detailed analysis of the structure. If nitrogen exists in a suitable form, such as an amine group, it can be adjusted. In this case, the decimal number may appear due to special bonding in the structure. After determining the structure, the accurate hydrogen deficiency index can be determined.
Third, the use of hydrogen deficiency index
In chemical industry practice, the hydrogen deficiency index can help chemists to initially judge the molecular structure. After knowing the value, a variety of possible structures can be set, and then proved by spectroscopy. In the analysis of the reaction mechanism, the reaction path can be explored according to the change of hydrogen deficiency index, indicating the change of unsaturation in the reaction. And when new compounds are created, the hydrogen deficiency index can be used as a standard for structural design, helping to determine the possible structure of the target product and speed up the synthesis process.
In summary, the hydrogen deficiency index is a powerful tool for exploring the molecular structure in chemical chemistry, and it is useful for analyzing the properties and reactions of substances.
In the field of chemical industry, the calculation of the Index of Hydrogen Deficiency (IHD) is quite important in order to understand the wonders of material structure. It can show the degree of molecular unsaturation and the clue of the analytical structure.
1. The principle of hydrogen deficiency index
The hydrogen deficiency index is to compare the studied molecule with the saturated chain hydrocarbon containing the same number of carbons to observe the difference in the number of hydrogen atoms. The general formula for saturated chain hydrocarbons is $C_nH_ {2n + 2} $. If the number of carbon in a molecule is $C $, the number of hydrogen is $H $, the number of halogen atoms is $X $, and the number of nitrogen atoms is $N $, then the hydrogen deficiency index is calculated as follows:
\ [IHD =\ frac {2C + 2 + N - H - X} {2}\]
The source of this formula is that every degree of unsaturation, or a double bond, or a ring, decreases the number of hydrogen atoms by two. The halogen atom has the same number of bonds as the hydrogen atom, so it can be regarded as hydrogen. The nitrogen atom forms a triple bond, and the introduction of a nitrogen atom is equivalent to adding a hydrogen atom.
Second, the calculation example shows
Example 1: Simple hydrocarbon
has a hydrocarbon molecule with the chemical formula $C_6H_ {10} $. Calculate its hydrogen deficiency index according to the above formula:
\ [IHD =\ frac {2\ times6 + 2 - 10} {2} =\ frac {12 + 2 - 10} {2} = 2\]
This shows that the molecule has two unsaturation degrees, or has a double double bond, or has a ring plus a double bond, or has two rings and other structures.
Example 2: If there is a halogen-containing nitrogen compound
, the chemical formula is $C_4H_7ClN $. Calculate its hydrogen deficiency index:
\ [IHD =\ frac {2\ times4 + 2 + 1 - 7 - 1} {2} =\ frac {8 + 2 + 1 - 7 - 1} {2} = 1.5\]
However, the hydrogen deficiency index must be an integer. Due to the complexity of the bonding of nitrogen atoms, the actual calculation requires detailed analysis of the structure. If nitrogen exists in a suitable form, such as an amine group, it can be adjusted. In this case, the decimal number may appear due to special bonding in the structure. After determining the structure, the accurate hydrogen deficiency index can be determined.
Third, the use of hydrogen deficiency index
In chemical industry practice, the hydrogen deficiency index can help chemists to initially judge the molecular structure. After knowing the value, a variety of possible structures can be set, and then proved by spectroscopy. In the analysis of the reaction mechanism, the reaction path can be explored according to the change of hydrogen deficiency index, indicating the change of unsaturation in the reaction. And when new compounds are created, the hydrogen deficiency index can be used as a standard for structural design, helping to determine the possible structure of the target product and speed up the synthesis process.
In summary, the hydrogen deficiency index is a powerful tool for exploring the molecular structure in chemical chemistry, and it is useful for analyzing the properties and reactions of substances.
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