Dehydration of Ethanol

Dehydration of ethanol take place in the presence of an acid. and this is three steps reaction. In this case, acid are consume and acid acid are release in reaction.

Reaction;

First step:- Formation of protonated alcohol

• In this case, first loan pair of oxygen from ethanol can be attracted to H+ ion. this mean, loan pair is to gives proton to form protonated alcohol.

Second steps: – Formation of carbocation

• In this steps, electron pair completely towards oxygen to form ethyl carbocation.

• Carbocation is one type of strong intermediate. because carbon have positive charge.

• It is eleminated in water molecules as shown in reaction. it is also known as carbonium ion.

Third steps:- Formation of ethene

• This is the last step, in this case H+ are eleminated to as a result it gives ethene.

• In this case, Acid are released.

• After the formation of ethene, proton are removed.

Ethanol dehydrating agent

Removel of water molecules (moisture) with chemically.

For examples,

Drying agent

Removel of water (moisture) with physically.

For example

Dehydration in tissue processing

Dehydration of tissue occur when the water consitutent of the tissue is removed.

Dehydration is important, because most of embedding are not miscible with water. and the removel of water facilitate the subsequent impregnation with the embedding media.

Dehydration is carryout by using the same reagent that mixed with both water and the ante – media.

Dehydration process (important point) for tissue processing,

If dehydration is not proper then tissue look like soft and will not allowed to infiltration of clearing agent.

Excess dehydration will results in hard and shrunken brittle tissue.

It is always advisable to process tissues and ascending grades of alcohol.

Ethyl alcohol and iso propyl alcohol is windly used in tissue processing. ethyl alcohol is best agent for dehydration in tissue process.

The dehydration is carry out by the using of the series of increasing strength of alcohol. such as, 50% , 70%, 80% , 90%, 100%. for delicate tissue like brain and embryos, dehydration will more gradual

beginning with 50% alcohol, with smaller intervals, with the different

grades of alcohols.

Diethylene dioxide

This makes it a unique dehydrating agent. it is also more used for dehydration process.

It is very little shrinkage to the tissue but it is not recommended for routine use because it is dangerous substance with little warning odor and a cumulative toxic action.

Dehydration of Ethanol

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