Alcohols Flashcards

1
Q

Name?

A

2-hydroxypropanenitrile

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2
Q

Whats a carbonyl group?

A

molecule containing C=O

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3
Q

What’s an aldehyde?
Structural formula?
Naming?

A

R–CH=O
…CHO
…al

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4
Q

What’s a ketone?
Structural formula?
Naming?

A

R–C=O–R
…CO
…one

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5
Q

What’s a carboxylic acid?
Structural formula?
Naming?

A

R–C=O–OH
…COOH
…oic acid

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6
Q

What 2 different methods are used to produce ethanol in the industry?

A
  • Direct hydration
  • Fermentation
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7
Q

What are the reagents + conditions for direct hydration?

A

Reagent: Conc. H3PO4 catalyst, steam
Conditions: 450 degrees, 50-100atm pressure

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8
Q

Fermentation reaction equation?

Reagent + Conditions needed?

A

C6H12O6 —–> 2CH3CH2OH + 2CO

Reagent: Glucose
Conditions: Yeast enzymes, 35 degrees, no oxygen

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9
Q

Explain why neither low or high temperature Is suitable for fermentation reaction?

A

Too cold - rate of reaction is too slow

Too high - enzymes denature + stop working

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10
Q

Pros + cons to production of ethanol through fermentation?

A

Advantages:
- Uses renewable resources (glucose)
- Lower temperatures require less energy cost
- Simpler equipment required is cheaper

Disadvantages:
- Slow RoR
- Land used to grow crops isn’t available for food crops
- Low yield
- Batch production is difficult to automate
- Ethanol is impure so needs to be distilled

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11
Q

Pros + cons to production of ethanol through direct hydration?

A

Advantages:
- High-purity ethanol produced
- Continuous production
- Fast RoR

Disadvantages:
- Crude oil is non-renewable
- High temperature + pressure requires energy
- High tech equipment

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12
Q

What are the following to go from Alcohol to Alkene in one step?

  • Reaction
  • Mechanism
  • Conditions
A
  • Dehydration
  • Elimination
  • Hot conc. H2SO4 (catalyst)
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13
Q

Elimination mechanism with ethanol to ethene?

A
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14
Q

What is the observation for alcohol oxidisation when acidified K2Cr2O7 is added?

A

Orange to Green

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15
Q

State the reagents + conditions needed to make a primary alcohol into an aldehyde?

A

Reagent: Acidified K2Cr2O7
Conditions: Heat under distillation

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16
Q

State the reagents + conditions needed to make an aldehyde into a carboxylic acid?

A

Reagent: Acidified K2Cr2O7
Conditions: Heat under reflux

17
Q

State the reagents + conditions needed to make a primary alcohol into a carboxylic acid?

A

Reagent: Acidified K2Cr2O7
Conditions: Heat under reflux, excess oxidising agent

18
Q

State the reagents + conditions needed to make a secondary alcohol into a ketone?

A

Reagent: Acidified K2Cr2O7
Conditions: Heat under reflux or distillation

19
Q

Out of primary alcohol, aldehyde + carboxylic acid, which one has the lowest boiling point? Why?

A

Aldehyde - permanent dipole-dipole forces, weakest IMF

Primary alcohol + carboxylic acid - hydrogen bonding

20
Q

Reflux apparatus?

A
21
Q

Distillation apparatus?

A
22
Q

Reagent used to test for aldehydes? (2)
Observation when not/present?

A

Tollen’s Reagent - [Ag(NH3)2]+
Present - Silver mirror forms
Not - No visible change

Fehling’s Solution - blue Cu2+
Present - Brick-red precipitate
Not - No visible change

23
Q

Reagent used to test for carboxylic acids?
Observation when not/present?

A

Sodium Carbonate - Na2CO3
Present - effervescence
Not - No visible change

24
Q

There are 3 problems with the apparatus of fractional distillation. For each problem:

  • Identify the problem
  • Describe the issue it would cause
  • Suggest how the problem can be solved
A

1) Anti-bumping granules:
- Add anti-bumping granules
- To create smaller bubbles/ prevent large bubbles

2) Open system with no thermometer:
- System should be closed to prevent gases escaping
- Closed with a bung and a thermometer
- To allow collection of propanone

3) The water direction in the condenser:
- Change water direction
- Condenser isn’t cool enough
- Product may not condense

25
Q

Explain why pentan-2-ol has a higher boiling point than pent-1-ene? (3)

A
  • Idea that pentan-2-ol has stronger intermolecular forces
  • Pent-1-ene has induced dipole-dipole forces (only)
  • Pentan-2-ol (also) has hydrogen bonds
26
Q

Explain why nonane has a higher boiling point than 2,4-dimethylheptane? (2)

A
  • Nonane has permanent dipole-dipole forces between molecules that are stronger than 2,4-dimethylheptane’s induced dipole-dipole forces
  • Nonane has more surface contact area