Chemistry of Alcohols and Their Oxidation

What color change indicates the reduction of potassium dichromate when oxidizing alcohols?

What is produced when alcohols are oxidized in the presence of acidified potassium dichromate?

What is the role of sulfuric acid in the dehydration of alcohols?

Which substance is used alongside sulfuric acid to catalyze the dehydration of alcohols?

What is the primary alcohol converted into during the fermentation process before dehydration?

What is the general formula for alcohols?

Which acid is commonly used as a catalyst in the hydration process for producing alcohols?

Why is the hydration method favored for industrial alcohol production?

What characteristic primarily distinguishes secondary alcohols from primary alcohols?

What is a common byproduct of heating primary alcohols in the presence of acidified potassium dichromate?

During fermentation, what is broken down by enzymes to produce alcohol?

What is the primary reason that fermentation is considered a slower process compared to hydration?

Which type of alcohol is not easily oxidized?

Alcohols

Alcohols contain an -OH functional group, with the general formula C_nH_2n+1OH
Production of alcohols can occur through two main methods: hydration and fermentation
Hydration method produces alcohols from alkenes and uses an acid catalyst (often phosphoric acid) under aqueous conditions (300°C & high pressure)
Hydration method is favored industrially as it has a very high percentage yield
Fermentation involves the use of enzymes to break down starch from crops into sugars, which are then fermented to form alcohol
Fermentation is cheaper than hydration as it can be carried out at lower temperatures, but is slower and has a lower percentage yield

Oxidation of Alcohols

Alcohols can be classified as primary (1°), secondary (2°) and tertiary (3°)
1° and 2° alcohols can be oxidized to produce various products, but 3° are not easily oxidized

Oxidation of primary alcohols

1° alcohols can be heated in the presence of acidified potassium dichromate and distilled to produce aldehydes
When heated further under reflux conditions, 1° alcohols can oxidise further to produce carboxylic acids

Oxidation of secondary alcohols

2° alcohols can be oxidized when heated in the presence of acidified potassium dichromate to produce ketones

Potassium Dichromate (K₂Cr₂O₇)

Used in the oxidation of alcohols as the oxidizing agent
It is reduced as the alcohol is oxidized, which can be observed as a color change from orange to green

Elimination Reactions

Alkenes can be formed from the dehydration of alcohols where a water molecule is removed
To achieve dehydration, excess hot sulfuric acid is added and aluminium oxide is used as a catalyst
This reaction allows for the production of addition polymers from fermentation without the need for crude oil
Fermentation produces the primary alcohol which is then dehydrated to produce an alkene used in the production of addition polymers

Explore the fascinating world of alcohols, including their functional groups, production methods such as hydration and fermentation, and the principles behind their oxidation. This quiz covers the classification of alcohols and their industrial significance. Test your knowledge on alcohol chemistry!

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