How to make ethylene 5, how to make ethylene

In the laboratory, ethanol and concentrated sulfuric acid are used (rapidly heated) at a temperature of 170 degrees Celsius to decompose to form ethylene.

C2H5OH = concentrated sulfuric acid = C2H4 + H2O

Industrially, it is produced from petroleum as a raw material.

CH3CH2OH (concentrated sulfuric acid and heating at 170 degrees Celsius (this must be this number)) H2C = CH2 H2O

Or acetylene and hydrogen additions will do.

Concentrated sulfuric acid and ethanol are reacted at 170 degrees to obtain ethylene.

Use the elimination reaction.

Concentrated sulfuric acid. ch3ch3oh**********ch2ch2+h2o

170 degrees Celsius.

Laboratory preparation of ethylene.

1) Reaction principle: CH3CH2OH concentrated sulfuric acid, 170 CH2 CH2 +H2O

2) Generating device: choose the reaction device of "liquid + liquid gas".

3) Collection method: drainage gas collection method (because the density of ethylene is close to the density of air and is insoluble in water).

4) Reaction type: elimination reaction.

5) Precautions:

The volume ratio of ethanol to concentrated sulfuric acid in the reaction solution is 1 3. The use of excess concentrated sulfuric acid can improve the utilization rate of ethanol and increase the production of ethylene.

A small amount of crushed porcelain pieces, zeolite, or other inert solids are added to the round-bottom flask to prevent the reaction mixture from boiling when heated.

The mercury ball of the thermometer should be inserted under the liquid surface to accurately determine the temperature of the reaction solution. When heating, the temperature should be rapidly raised to 170 to reduce the chance of ether formation (ether will be formed at 140).

In the reaction of preparing ethylene, concentrated sulfuric acid is not only a catalyst, a water absorbent, but also an oxidizing agent, which is easy to oxidize ethanol during the reaction process, and finally generates CO2, CO, C, etc. (so the liquid in the test tube turns black), and the sulfuric acid itself is reduced to be able to fade bromine water or KMno4 solution. Therefore, before doing the property test of ethylene, the gas should be removed by alkali lime to remove SO2, or the gas can be washed by 10% NaOH solution to remove SO2 to obtain purer ethylene.

If the ethylene contained in the air is very easy to meet an open flame, it is more violent than methane, so be careful when igniting ethylene.

Ethanol for laboratory vinyl production.

Catalytic dehydration to produce ethylene.

The chemical equation is:

CH3CH2OH — concentrated sulfuric acid.

170°c —ch 2 =ch 2 +h 2 o<>

Under the catalytic action of concentrated sulfuric acid, ethanol is used in the laboratory to produce ethylene when heated to 170. Equation: CH3CH2OH - concentrated sulfuric acid, 170 )-CH2 = CH2 + H2O

Ethylene is produced by ethanol heated to 170 degrees under the catalysis of concentrated sulfuric acid, and the elimination reaction occurs.

Preparation method of ethylene: reaction equation: C2H5OH = concentrated sulfuric acid = CH2CH2 + H2O.

Materials required for the experiment] ethanol, concentrated sulfuric acid, alcohol lamp, iron frame, broken porcelain pieces, bromine water.

Problems that need to be paid attention to in the process of producing ethylene in the laboratory:

1.Concentrated H2SO4 acts as a catalyst and dehydrating agent, and zeolite or crushed porcelain chips act as a catalyst and dehydrator.

2.The concentrated H2SO4 was mixed with ethanol according to the volume ratio of 3 1, and the reason for the excess of concentrated H2SO4 was to promote the reaction to the direction of the positive reaction.

3.The temperature should rise rapidly to 170 to prevent the formation of by-product ether at 140. This reaction is a substitution reaction rather than a elimination reaction.

4.The reason why the coding reaction solution turns black when making ethylene is that the ethanol has a redox reaction with concentrated H2SO4, so the ethylene prepared in the laboratory may also be mixed with impurity gases such as CO2 and SO2.

Ethylene preparation is an industrial method: the ethylene used in industry is mainly separated from the gas produced by petroleum refining plants and petrochemical plants. Laboratory Method:

In the laboratory is to put alcohol andConcentrated sulfuric acid is a few stoolsMix 1:3 and heat quickly to 170 to make the alcohol decompose. Concentrated sulfuric acid acts as a catalyst and dehydrator in the reaction process.

Ethylene is a synthetic fiber, synthetic rubber, synthetic plastic (polyethylene and polyvinyl chloride.

Synthesis of ethanol. alcohol) is also used in the manufacture of vinyl chloride, styrene, ethylene oxide, acetic acid.

Acetaldehyde and explosives, among others, can also be used as ripening agents for fruits and vegetables, and is a proven plant hormone.

Main uses of ethylene:

1. Ethylene is an important basic raw material for organic chemicals, mainly used in the production of polyethylene, ethylene propylene rubber, polyvinyl chloride, etc.

2. One of the most basic raw materials of petrochemical industry. In terms of synthetic materials, the bulk is used in the production of polyethylene, vinyl chloride and polyvinyl chloride, ethylbenzene, styrene and polystyrene.

and ethylene propylene rubber, etc.

In terms of organic synthesis, Biyuan is widely used in the synthesis of ethanol, ethylene oxide and ethylene glycol.

acetaldehyde, acetic acid, propionaldehyde, propionic acid and its derivatives and other basic organic synthesis raw materials; After halogenation, it can be used to produce chlorinated ethylene, chloroethane and bromoethane; It can be made into olefins by oligomerization.

And then produce higher alcohols, alkylbenzene, etc.

3. It is mainly used as the standard gas for analytical instruments in petrochemical enterprises.

4. Ethylene is used as an environmentally friendly ripening gas for navel oranges, tangerines, bananas and other fruits.

5. Ethylene is used in pharmaceutical synthesis and high-tech material synthesis.

In the laboratory, alcohol and concentrated sulfuric acid are mixed at 1:3 and quickly heated to 170 to decompose the alcohol. Concentrated sulfuric acid acts as a catalyst and dehydrator in the reaction process. The reaction of preparing ethylene belongs to the liquid simple land-liquid heating type.

Ethylene is a compound made up of two carbon atoms and four hydrogen atoms. The two carbon atoms are connected by a double bond with each other. Ethylene exists in some tissues and organs of plants, and is converted from methionine under the condition of sufficient oxygen supply.

Ethylene is the basic chemical raw material for synthetic fibers, synthetic rubber, synthetic plastics (polyethylene and polyvinyl chloride), synthetic ethanol (alcohol), and is also used in the manufacture of vinyl chloride, styrene, ethylene oxide, acetic acid, acetaldehyde, ethanol and explosives, etc., and can also be used as a ripening agent for fruits and vegetables, and is a proven plant hormone.

ch = ch + h = ch ch (conditional catalyst, heated).

Normally, ethylene is a colorless and slightly odorous gas with a density of slightly less dense than air, insoluble in water, and easily soluble in organic solvents such as carbon tetrachloride.

Appearance and properties: colorless gas, slightly odorous with hydrocarbons. A small amount of ethylene has a faint sweetness.