3.5 - Alcohols Flashcards by Martin Hush

Why is a compromise temperature of 35°C used in fermentation?

Greater than 40°C denatures Yeast

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Raw Material: Hydration of Ethene

Crude Oil

finite

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Three uses of Ethanol?

Alcohol Drinks
Solvent
Feedstock for Chemical processes (reactant)

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What are the functional Group isomers of alcohols?

Ethers

C-O-C

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Define: Biofuel

Fuel derived/produced from Recently living, Renewable Biological sources

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Why is using Biofuels not completely Carbon Neutral?

Fossil fuels burned to power machinery:
|> Make fertilisers
|> Harvest crops
|> Refine fuel
|> Transport fuel
Produces CO₂

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What provides H⁺ in the Elimination of Alcohols?

Acid Catalyst

H₂SO₄

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Type of Process: Hydration of Ethene

Addition

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Reagents for Fermentation?

Sugar Crop (glucose)
Yeast

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Conditions for Fermentation?

Aqueous

Anaerobic

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Raw Material: Fermentation

Sugar Crops

renewable

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How can Alcohols be prepared from Alkenes?

Hydration

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3 Disadvantages of using Crops to produce Fuels?

|> Land used to grow crops for fuel can’t be used to grow food
|> Fertilisers added to soil put algae into rivers
|> Deforestation to create land for crops to grow

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Atom economy: Fermentation

51.1%

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Use of long chain Alcohols?

Soap

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What is a tertiary alcohol?

Alcohol where connected Carbon is connected to 3 other Carbons

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Define: Structural isomers

Compounds w/ same molecular formula but a different Structural formula

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How is an Alcohol named in terms of Position of O-H?

Alcohol no. must be lowest possible

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In Hydration of Alkenes, what is the role of H₃PO₄?

Acid Catalyst

Provides H⁺ ions

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Energy requirements: Hydration of Ethene

High

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Quality of Product: Hydration of Ethene

100% Pure

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Rate of Reaction: Hydration of Ethene

Fast

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Functional Group of Alcohols?

C-OH

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Define: Chain isomers

Isomers w/ same molecular formula but different Carbon chain arrangement

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What do Alcohols react to form in Elimination Reactions?

An Alkene

In mechanisms, what does a Double-headed curly arrow show?

Movement of a pair of Electrons

What is Eliminated in the Elimination of Alcohols?

Water

Since Water is Eliminated, what does the Elimination of Alcohols involve?

Dehydration

3 reactions that Alcohols take part in?

Combustion Elimination Oxidation

Define: Functional Group isomers

Isomers w/ same molecular formula but different functional group

Define: Position isomers

Isomers w/ same molecular formula but functional group is in a different position

What is a Secondary alcohol?

Alcohol where connected Carbon is connected to 2 other Carbons

Why are longer alcohols Not Soluble in Water

Strength of VDWs outweighs that of | Hydrogen bonds

The first few alcohols are soluble in ____ ?

Water

When writing equations of Combustion of Alcohols, what must be taken note of?

The O atom in the Alcohol

Atom economy: Hydration of Ethene

100%

Quality of Product: Fermentation

Very Impure

General formula of Alcohols?

CnH₂n₊₁OH

When Alcohols burn in Oxygen what is formed?

CO₂ & H₂O

Rate of Reaction: Fermentation

Slow

Why does Fermentation stop when reaction mixture contains around 15% Ethanol?

Ethanol denatures Yeast

Define: Carbon Neutral fuel

Fuel that uses same amount of CO₂ from atmosphere when produced as is released when burned

Energy requirements: Fermentation

Low

General Equation for Hydration of Alkenes?

(H,R)-C=C-(H,R) + H₂O(g) |(H⁺)> RCH₂CH(OH)R

Alcohols have ____ boiling points than their corresponding alkane?

Higher

What is a Primary Alcohol

Alcohol where connected Carbon is only connected to 1 other Carbon

Type of Process: Fermentation

Decomposition

Reagents for Hydration of Ethene?

H₂O(g) - Steam | H₃PO₄ - Phosphoric Acid Catalyst

Reagent of Elimination of Alcohols?

Concentrated H₂SO₄ (98%)

Conditions for Hydration of Ethene?

300°C | 60 atm

Conditions for Elimination of Alcohols?

Warm

Conditions for Hydration of Alkenes?

300°C | 60 atm

What are the 2 different methods for the Industrial Preparation of Ethanol?

Fermentation | Hydration of Ethene

Why do Alcohols have Higher Boiling Points than their corresponding Alkane?

Alcohols form hydrogen bonds whereas alkanes only form VDWs

Why might Fermentation followed with Elimination be used to make Ethene in the future?

More economical than: | Fractional Distillation |> Cracking |> Polymerisation

3 Steps of Fermentation?

|> Carbohydrates from crops (e.g. Sugar Cane, Sugar Beet) are Broken Down into Sugars (e.g. Glucose) |> Sugars converted into Ethanol through Anaerobic Respiration |> Ethanol removed from reaction mixture by Distillation

Reagent for Hydration of Alkenes?

H₂O(g) - Steam | H₃PO₄ - Phosphoric Acid Catalyst

Equation for Atom Economy?

Mr Useful Product / Total Mr of all Products x 100

Why is the Elimination reaction of Alcohols very important?

Renewable source of Plastics

Equation for Fermentation to produce Ethanol?

C₆H₁₂O₆ |> 2C₂H₅OH + 2CO₂

Why is Air kept out of a Fermentation reaction?

Prevents further Oxidation | Prevents formation of Carboxylic Acid

Why do Alcohols Combust more Efficiently than Alkanes?

Presence of O atom in the molecule

What Type of Reaction is the Hydration of Alkenes?

Addition