Organic synthesis

Question 1

What is the general formula for alkanes?

Answer 1

C_nH_(2n+2)

Question 2

True or False: Alkenes are saturated hydrocarbons.

Answer 2

False

Question 3

Fill in the blank: The process of converting an alkene to an alkane is called __________.

Answer 3

hydrogenation

Question 4

What functional group characterizes alcohols?

Answer 4

Hydroxyl group (-OH)

Question 5

Which reaction involves the substitution of a halogen in an alkane?

Answer 5

Free radical substitution

Question 6

True or False: Carboxylic acids can act as both acids and bases.

Answer 6

True

Question 7

What is the primary product when a carboxylic acid reacts with an alcohol?

Answer 7

Ester

Question 8

Name the reaction type that forms an amide from a carboxylic acid.

Answer 8

Condensation reaction

Question 9

What is the main reagent used for the reduction of aldehydes?

Answer 9

NABH4 (Sodium borohydride)

Question 10

Which reagent is commonly used to oxidize primary alcohols to aldehydes?

Answer 10

Potassium dichromate (K2Cr2O7)

Question 11

What is the key feature of a nucleophilic substitution reaction?

Answer 11

A nucleophile replaces a leaving group.

Question 12

True or False: Benzene is a saturated compound.

Answer 12

False

Question 13

What is the mechanism of electrophilic substitution in aromatic compounds?

Answer 13

The electrophile replaces a hydrogen atom on the benzene ring.

Question 14

Fill in the blank: The product of a nitration reaction of benzene is __________.

Answer 14

Nitrobenzene

Question 15

What is the role of sulfuric acid in the synthesis of esters?

Answer 15

Catalyst

Question 16

Which type of reaction is used to form alkenes from alcohols?

Answer 16

Dehydration reaction

Question 17

What is the effect of increasing the chain length on the boiling point of alkanes?

Answer 17

The boiling point increases.

Question 18

True or False: Ethers can be hydrolyzed to form alcohols.

Answer 18

True

Question 19

What is the primary use of thin-layer chromatography (TLC) in organic analysis?

Answer 19

To separate and identify compounds.

Question 20

What does the retention factor (Rf) indicate in chromatography?

Answer 20

The distance traveled by the compound relative to the solvent front.

Question 21

Fill in the blank: The process of breaking down a compound into simpler substances is called __________.

Answer 21

decomposition

Question 22

What type of reaction occurs when an alkene reacts with a halogen?

Answer 22

Electrophilic addition

Question 23

Name one method of preparing alkenes from alkanes.

Answer 23

Cracking

Question 24

True or False: Primary alcohols can be oxidized to carboxylic acids.

Answer 24

True

Question 25

What is the main product of the hydrolysis of esters?

Answer 25

Carboxylic acid and alcohol

Question 26

What is the significance of using a reflux apparatus in organic synthesis?

Answer 26

To heat a reaction mixture without losing volatile components.

Question 27

Which spectroscopy technique is used to determine the structure of organic compounds by measuring the vibrations of bonds?

Answer 27

Infrared spectroscopy (IR)

Question 28

Fill in the blank: The process of heating a compound with a strong acid to break it down is called __________.

Answer 28

acid hydrolysis

Question 29

What type of isomerism is exhibited by alkenes?

Answer 29

Geometric (cis-trans) isomerism

Question 30

True or False: All alcohols can form hydrogen bonds.

Answer 30

True

Question 31

What is the role of a drying agent in organic synthesis?

Answer 31

To remove water from organic solvents.

Question 32

Name the type of reaction where two molecules combine to form a larger molecule with the loss of a small molecule.

Answer 32

Condensation reaction

Question 33

What is the common name for ethanoic acid?

Answer 33

Acetic acid

Question 34

Fill in the blank: The reaction of an acid and a base to form a salt and water is called __________.

Answer 34

neutralization

Question 35

What type of chemical reaction occurs when a compound loses electrons?

Answer 35

Oxidation

Question 36

What is the main characteristic of a primary amine?

Answer 36

One alkyl group attached to the nitrogen atom.

Question 37

True or False: Aromatic compounds are more reactive than aliphatic compounds.

Answer 37

False

Question 38

What is the purpose of recrystallization in organic chemistry?

Answer 38

To purify solid compounds.

Question 39

What is needed to turn nitrobenzene into phenylamine?

Answer 39

Reduction using Sn and concentrated HCl.

Question 40

How do you convert ethene into ethanoic acid?

Answer 40

Add H2SO4 with water and reflux with acidified potassium dichromate.

Question 41

What reagents are needed to convert benzene into 1-phenylpropanone?

Answer 41

Friedel-Crafts acylation using propanoyl chloride and AlCl3.

Question 42

What must be thoroughly investigated before commercial production of a compound?

Answer 42

Effectiveness, safety, side effects, and so on.

Question 43

What is the first step in working out a synthesis scheme?

Answer 43

Write down the formula of the starting molecule (A) and the target molecule (X).

Question 44

List the functional groups you should know for organic synthesis.

Answer 44

* Alkanes * Alkenes * Halogenoalkanes * Alcohols * Amines * Aldehydes * Ketones * Acid derivatives * Arenes

Question 45

What does 'yield' measure in organic synthesis?

Answer 45

The efficiency of the conversion of a starting material into a product.

Question 46

Why is it important to keep the number of steps in a synthesis scheme small?

Answer 46

To maximise the yield of the target.

Question 47

Fill in the blank: The reaction of cyanide ions with a __________ will be needed if the target molecule has one more carbon atom than the starting material.

Answer 47

halogenoalkane

Question 48

How do you convert propanone into 2-bromopropane?

Answer 48

Reduce with NaBH4 to to propan-2-ol and then react with KBr/H2SO4

Question 49

What potential does the target compound have after synthesis?

Answer 49

Potential for use in reactions and processes.

Question 50

What is the significance of atom economy in organic synthesis?

Answer 50

It relates to the efficiency of the conversion process.

Question 51

How do you convert cyclohexanol into cyclohexene?

Answer 51

Dehydrate with P2O5

Question 52

How do you turn but-1-ene into butanone?

Answer 52

Conc. sulphuric acid with water and then oxidise with acidified potassium dichromate

Question 53

What do you need to turn ethanoic acid into methyl ethanoate?

Answer 53

Methanol with an acid catalyst

Question 54

What reagent do you need to make but-1-ene into butan-2-ol?

Answer 54

Conc. sulphuric acid with water

Question 55

What should you react 1-bromobutane with to get pentanenitrile?

Answer 55

Potassium cyanide

Question 56

What is the role of hydrogen and nickel in turning a nitrile into an amine?

Answer 56

Hydrogen reduces the nitrile and nickel acts as a catalyst

Question 57

Fill in the blank: Secondary alcohols are oxidised to _______.

Answer 57

ketones ## Footnote This is part of the oxidation process in organic chemistry.

Question 58

What oxidising agent is used to oxidise primary alcohols to aldehydes?

Answer 58

Potassium dichromate (VI) ## Footnote It is acidified with dilute sulfuric acid for this reaction.

Question 59

What is the outcome of oxidising aldehydes?

Answer 59

Carboxylic acids ## Footnote Aldehydes can be further oxidised to form carboxylic acids.

Question 60

What should you be able to recall regarding functional groups?

Answer 60

Reactions and conditions such as heating, refluxing, acidic or alkaline conditions, and catalysts ## Footnote Understanding these aspects is crucial for organic synthesis.

Question 61

True or False: Propylamine can be made from ethene.

Answer 61

True ## Footnote Ethene can be made into a haloalkane and then reacted with KCN

Question 62

What is the significance of the inter-relationships between functional groups?

Answer 62

They help in revising knowledge of organic reactions ## Footnote Understanding these relationships is key to successful synthesis.

Question 63

What is a common method to produce a library of aldehydes from alcohols?

Answer 63

Oxidising several alcohols of different chain lengths ## Footnote This method allows for the exploration of various compounds' medicinal potential.

Question 64

Fill in the blank: The reaction of cyanide is an example of a reaction that may involve _______.

Answer 64

functional groups ## Footnote This highlights the importance of functional groups in synthetic reactions.