3.5 - Alcohols 2

Question 1

Observation is Aldehyde present & Oxidised w/ Tollens’ Reagent?

Answer 1

Ag⁺ + e⁻ |> Ag(s)

Silver Mirror

Question 2

Oxidation product of Secondary Alcohols?

Answer 2

Ketone

Question 3

What can the Organic tests be used to Confirm?

Answer 3

Presence & Identity of Organic Impurities

Question 4

Oxidation product of Primary Alcohols?

Answer 4

Aldehyde

Carboxylic Acid

Question 5

Organic product when a Carboxylic Acid reacts with Na₂CO₃?

Answer 5

Carboxylate Salt

e.g. Sodium Ethanoate

Question 6

Will Ketones React with either Tollens’ Reagent or Fehling’s solution?

Answer 6

No - Ketones cannot be oxidised

Question 7

Oxidising Agent in Oxidation of Alcohols?

Answer 7

Acidified Potassium Dichromate

H⁺/Cr₂O₇²⁻

Question 8

General Equation of Oxidation of Aldehyde?

Answer 8

R-C(=O)-H + [O] |> R-C(=O)-OH

Question 9

Test for Presence of Aldehydes?

Answer 9

Mild Oxidising Agents:

e. g. Tollens’ Reagent
e. g. Fehling’s solution

Question 10

Observation when Carboxylic Acid reacts with Na₂CO₃?

Answer 10

Fizz

CO₂ produced

Question 11

General Equation of Oxidation of Secondary Alcohols?

Answer 11

R-C-(H,OH)-R + [O] |> R-C(=O)-R + H₂O

Question 12

Can Ketones be Oxidised further?

Answer 12

No

Question 13

Why is the Product of Oxidation of a Primary Alcohol most likely to be an Aldehyde when formed through Immediate Distillation?

Answer 13

Aldehyde has Lower Boiling Point than Alcohol
(pd-pd weaker than H-bond)

Turns into a gas & cannot react further

Question 14

Observations for Oxidation of Secondary Alcohols

Answer 14

Orange |> Green

Question 15

In Organic Chemistry, what is Oxidation?

Answer 15

Creation of more C-O bonds

Question 16

General Equation for Oxidation of a Primary Alcohol to a Carboxylic Acid?

Answer 16

R-CH₂-OH + 2[O] |> R-C(=O)-OH + H₂O

Question 17

How can H⁺/Cr₂O₇²⁻ be used to identify Tertiary Alcohols?

Answer 17

No Observable Change

Question 18

Observations for Oxidation of a Primary Alcohol to an Aldehyde?

Answer 18

Orange |> Green

Question 19

How is Fehling’s solution formed?

Answer 19

Add Fehling’s 1 to Fehling’s 2

Copper Sulfate to Potassium Sodium Tartrate

Question 20

Organic product when Aldehyde present & Oxidised with Fehling’s solution?

Answer 20

Carboxylic Acid

Question 21

What is formed when a Secondary Alcohol is Oxidised?

Answer 21

Ketone

Question 22

General Equation for reaction of Carboxylic Acid with Na₂CO₃?

Answer 22

2R-C(=O)-OH + Na₂CO₃ |> 2R-C(=O)-O⁻Na⁺ + CO₂ + H₂O

Question 23

Test for Presence of a Carboxylic Acid?

Answer 23

Add Sodium Carbonate

Na₂CO₃

Question 24

Organic product when Aldehyde present & Oxidised with Tollens’ Reagent?

Answer 24

Carboxylic Acid

Question 25

Observations if Aldehyde present & Oxidised with Fehling's solution?

Answer 25

Cu²⁺(aq) |> Cu₂O(s) | Blue solution |> Brick red ppt

Question 26

Oxidation product of Tertiary Alcohols?

Answer 26

Not Oxidised No Reaction No H on Carbon to remove

Question 27

How is the Carboxylic Acid removed from the reaction mixture?

Answer 27

Distillation

Question 28

How is an Aldehyde denoted in naming, structural formula & numbering?

Answer 28

-Al -CHO No number, always named as end Carbon

Question 29

Reagents & Conditions for Oxidation of Secondary Alcohols?

Answer 29

Acidified Potassium Dichromate (VI) | Reflux

Question 30

General Equation for Oxidation of a Primary Alcohol to an Aldehyde?

Answer 30

R-CH₂-OH + [O] |> R-CHO + H₂O

Question 31

Reagents & Conditions for Oxidation of a Primary Alcohol to a Carboxylic Acid?

Answer 31

Acidified Potassium Dichromate (VI) | Reflux

Question 32

In balanced equations, what can the Oxidising Agent be simplified to?

Answer 32

[O]

Question 33

Observations for Oxidation of a Primary Alcohol to a Carboxylic Acid?

Answer 33

Orange |> Green

Question 34

Reagents & Conditions for Oxidation of a Primary Alcohol to an Aldehyde?

Answer 34

Acidified Potassium Dichromate (VI) | Distillation

Question 35

How is Tollens' Reagent formed?

Answer 35

Add NaOH to AgNO₃ until brown precipitate formed Add NH₃ until ppt dissolves

Question 36

Why is the product of Oxidation of a Primary Alcohol most likely to be a Carboxylic Acid when formed through Reflux?

Answer 36

Aldehyde is Recondensed back into the flask so further Oxidation can occur

Question 37

Define: Reflux

Answer 37

Boiling without gas escaping