High School Chemistry Equivalent Hydrogen, What do you think about the equivalent hydrogen in High S

This concept is generally found in organic chemistry.

H atoms that are in the same environment in the structure of a compound are called equivalent hydrogen. For example, in ch3ch2ch2ch3, the three Hs connected to the leftmost carbon are connected to the same C in the same environment, and no matter which of the three hydrogen atoms changes, the effect is the same as that of one of the other two hydrogen atoms. For H on the leftmost carbon and H on the second C, the environment is different, they are not equivalent to hydrogen.

Some ways to judge hydrogen equivalent:

The hydrogen attached to a carbon atom on the most edge is the equivalent hydrogen. For example, the three Hs on the leftmost carbon in ch3ch2ch2ch3 and the three hydrogens on the rightmost carbon.

H attached on a symmetrical c atom is equivalent to hydrogen. For example, the two leftmost and rightmost carbons in ch3ch2ch3 are symmetrical, and the six hydrogens connected to them are equivalent hydrogen. The second carbon and the penultimate carbon are symmetrical, and the four hydrogens connected to them are equivalent hydrogen.

Note: The most effective way to determine hydrogen equivalence is based on symmetry.

Refers to hydrogen atoms that have the same effect after substitution.

It refers to a monovalent substance, which is equivalent to h after being replaced!!

ch3)2chch2ch2ch3 has 5 equivalent hydrogen, so it can be seen that the last three are 4, 2, and 3 respectively.

Remember, methyl on the same carbon is equivalent, hydrogen on the same carbon is equivalent, and hydrogen with a symmetrical structure is also equivalent.

In chemical reactions, equivalent hydrogen is seen in this way, 1The sentiment on the same carbon is equivalent to hydrogen, 2Hydrogen on symmetrical carbon is equivalent hydrogen, 3Hydrogen on methyl groups on the same carbon is also equivalent hydrogen.

Equivalent hydrogen atoms: 1, hydrogen equivalent to the same carbon atom 2, hydrogen in a symmetrical position equivalent to hydrogen on methyl groups connected to the same carbon atom. To find the equivalent hydrogen atom, first look at whether the organic matter has a symmetry axis, so the equivalent hydrogen atom of the organic matter is as follows:

A1 B 4 C 4 D 3 Hydrogen, so the answer is D.

In fact, the key is to write the structure of organic matter (in fact, it is enough to write carbon chains), and find his axis of symmetry. The symmetrical hydrogen atoms are the same after the organic matter rotates along the axis of symmetry at a certain angle, so the corresponding hydrogen atoms belong to the equivalence relationship. As.

a： c c

c—c—c—c is symmetrical left and right, and symmetrical up and down, so the six surrounding hydrogen atoms are actually equivalent.

c c

d. Correct: A 1 group of peaks, b and c are 4 groups of peaks;

Method: Simply draw the carbon chain structure of each substance, and then analyze whether the types of carbon atoms connected by various carbon atoms are the same, the same is the same carbon atom, and the hydrogen on the carbon atom is also the same kind of hydrogen atom.

Because when you write the whole chain of substituents, horizontally or vertically, but the bond angle is not 90°.

Saturated carbon should be a tetrahedral type, and the single bond of this tetrahedron can be rotated without considering steric hindrance.

The symmetry factor of that benzene ring is this axis of symmetry:

It can be seen that the two hydrogen atoms in the blue circle on this axis of symmetry are equivalent hydrogen atoms, and the two hydrogen atoms in the green circle are equivalent hydrogen atoms. Hence there are two kinds of equivalent hydrogen atoms on the benzene ring.

There is one equivalent hydrogen, so there is 1 monochlorofibrous front substitute and 1 methyl group, namely: Raider CH3Cl

There is an equivalent hydrogen, so there is 1 monochlorosubstituent and 1 methyl group, i.e., CH3CH2Cl

Equivalent hydrogen atom method (also known as symmetry method): The molecular equivalent hydrogen atom has the following conditions:

Hydrogen atoms attached to the same carbon atom in a molecule are equivalent.

The hydrogen atom on the methyl group attached to the same carbon atom is equivalent. For example, neopentane (which can be seen as four methyl groups replacing four hydrogen atoms in the methane molecule), its four methyl groups are equivalent, and the hydrogen atoms on each methyl group are completely equivalent, that is, the 12 h atoms in the neopentane molecule are equivalent.

The hydrogen atoms in the molecule in a mirror symmetrical position (equivalent to the object-image relationship in the case of plane mirror imaging) are equivalent.

Using the equivalent hydrogen atomic relationship, it is easy to determine the number of monovariant isomers of organic matter. The method is to first observe the number of hydrogen atoms in the molecule that are not equivalent to each other, and then the structure of the monovariant substitute. For example, there is only one monochlorogenated neopentane (2,2,3,3-tetramethylbutane); There are 2 kinds of monochlorogenated propane (6 H atoms on two methyl groups in CH3-CH2-CH3, two hydrogen atoms on methylene groups, and 2 unequal H atoms in the molecule).

Draw the axis of symmetry, and hydrogen on both methyl and hypomethyl groups are equivalent.

The same amount of hydrogen is attached to the same carbon;

The methyl group attached to the same carbon is the same, and the hydrogen is also the same;

The position on the benzene ring depends on the position, the same position or complete symmetry.