6. Fundamentals of Organic and Inorganic Chemistry

Question 1

What is Catalytic hydrogenation?

Answer 1

This is a catalytic chemical reaction between H2 and another compound aiming at reducing or saturating organic compounds. Hydrogens are typically added in pairs to a molecule, often an alkene. Common catalysts include nickel, palladium, and platinum. The presence of a catalyst significantly reduces the temperature required for the process to take place.

Question 2

What is Cis-trans isomerization?

Answer 2

This isomerism also called geometric isomerism or configurational isomerism concerns spatial arrangements with prefixes cis and trans used to identify the substitution of some atoms on one side and the other side of a plane.

Question 3

Explain electron dislocation.

Answer 3

This occurs when all six carbons in a ring attract electrons (opposed to only one or two, which is the case in covalence bonds). This dislocation causes the structure to hold the electrons more tightly, making benzene a more stable and less reactive molecule compared to other unsaturated hydrocarbons.

Question 4

What is organic chemistry?

Answer 4

Organic chemistry is the study of carbon-containing compounds.

Question 5

What was the historical belief about organic compounds?

Answer 5

Organic compounds were thought to come only from living organisms.

Question 6

Who disproved this idea and how (organic compounds)?

Answer 6

In 1828, Friedrich Wöhler synthesized urea from inorganic compounds, proving that organic compounds can be created in a lab.

Question 7

What three main concepts distinguish organic chemistry from inorganic chemistry?

Answer 7

Functional group classification
Naming process
How compounds react to form new substances

Question 8

What are hydrocarbons?

Answer 8

Organic compounds made up of only carbon (C) and hydrogen (H).

Question 9

What are the two main types of hydrocarbons?

Answer 9

Aliphatic hydrocarbons – Straight-chain or cyclic compounds (e.g., alkanes, alkenes, alkynes, cycloalkanes).
Aromatic hydrocarbons – Contain benzene rings with alternating single and double bonds.

Question 10

What is hybridization in organic chemistry?

Answer 10

The mixing of atomic orbitals to explain molecular geometry and bonding.

Question 11

How does hybridization explain the structure of methane (CH₄)?

Answer 11

Carbon undergoes sp³ hybridization, allowing it to form four covalent bonds with hydrogen.

Question 12

What are alkanes?

Answer 12

Alkanes are saturated hydrocarbons with only single bonds between carbon atoms.

Question 13

What is the general formula of alkanes?

Answer 13

CₙH₂ₙ₊₂

Question 14

Why are alkanes called “saturated hydrocarbons”?

Answer 14

They contain the maximum number of hydrogen atoms possible.

Question 15

What are the first two alkanes?

Answer 15

Methane (CH₄)
Ethane (C₂H₆)

Question 16

What is a key property of alkanes?

Answer 16

They are not very reactive, but they are excellent fuels due to their exothermic combustion reactions.

Question 17

What are structural isomers?

Answer 17

Compounds with the same molecular formula but different structures.

Question 18

What are cycloalkanes?

Answer 18

Alkanes that form a ring structure instead of a straight chain.

Question 19

What is the general formula for cycloalkanes?

Answer 19

CₙH₂ₙ (two fewer hydrogen atoms than regular alkanes).

Question 20

What is the smallest cycloalkane?

Answer 20

Cyclopropane (C₃H₆)

Question 21

Where are cycloalkanes found?

Answer 21

In biological molecules like sugars and hormones.

Question 22

What are alkenes?

Answer 22

Unsaturated hydrocarbons that contain at least one double bond (C=C).

Question 23

What is the general formula for alkenes?

Answer 23

CₙH₂ₙ

Question 24

What is the simplest alkene?

Answer 24

Ethylene (C₂H₄) – Used in plastic production.

Question 25

What is cis-trans isomerism?

Answer 25

A type of stereoisomerism where molecules with the same formula have different spatial arrangements due to restricted rotation around a double bond.

Question 26

What are alkynes?

Answer 26

Unsaturated hydrocarbons with at least one triple bond (C≡C).

Question 27

What is the general formula for alkynes?

Answer 27

CₙH₂ₙ₋₂

Question 28

What is the simplest alkyne?

Answer 28

Ethyne (Acetylene, C₂H₂) – Used in welding.

Question 29

Are alkynes common in nature?

Answer 29

No, they are rare in nature but important in industry.

Question 30

What is the parent compound of aromatic hydrocarbons?

Answer 30

Benzene (C₆H₆).

Question 31

What makes benzene unique?

Answer 31

It has alternating single and double bonds that create a delocalized electron cloud, leading to high stability.

Question 32

Why does benzene undergo substitution reactions instead of addition reactions?

Answer 32

Addition reactions would disrupt the resonance stability of the benzene ring.

Question 33

What is electron delocalization?

Answer 33

The free movement of electrons in the benzene ring, contributing to its stability.

Question 34

What are sigma (σ) bonds?

Answer 34

Single covalent bonds formed by head-on overlap of orbitals.

Question 35

What are pi (π) bonds?

Answer 35

Weaker bonds formed by side-by-side overlap of orbitals in double and triple bonds.

Question 36

Which is stronger: a sigma bond or a pi bond?

Answer 36

Sigma bonds are stronger because they allow for more effective orbital overlap.

Question 37

How do sigma and pi bonds relate to bond stability?

Answer 37

Alkanes (single bonds) are more stable than alkenes (double bonds) and alkynes (triple bonds) due to having only sigma bonds.

Question 38

Why are alkanes used as fuels?

Answer 38

They undergo combustion reactions, which release large amounts of energy.

Question 39

What is halogenation?

Answer 39

A reaction where hydrogen atoms are replaced by halogens (e.g., chlorine, fluorine).

Question 40

How are alkenes produced industrially?

Answer 40

Through catalytic cracking of larger hydrocarbons in crude oil.

Question 41

Why is ethylene (C₂H₄) important in industry?

Answer 41

It is the main raw material for making plastics (e.g., polyethylene).

Question 42

What makes acetylene (C₂H₂) useful for welding?

Answer 42

It has a high heat of combustion, making it a powerful fuel.

Question 43

What are functional groups in organic chemistry?

Answer 43

✅ Functional groups are specific atom combinations that influence a compound’s reactivity and chemical behavior.

Question 44

❓ Why are functional groups important?

Answer 44

✅ They determine reaction types, solubility, and physical properties of organic compounds.

Question 45

❓ What is the functional group of alcohols?

Answer 45

✅ The hydroxyl group (-OH).

Question 46

❓ How are alcohols related to water?

Answer 46

✅ They can be considered organic derivatives of water, where one hydrogen is replaced by an alkyl group.

Question 47

❓ Are alcohols strong acids?

Answer 47

✅ No, alcohols are weak acids and only partially dissociate in water.

Question 48

❓ What is the most common alcohol?

Answer 48

✅ Ethanol (ethyl alcohol, C₂H₅OH).

Question 49

❓ How is ethanol produced?

Answer 49

Fermentation of sugars Hydration of ethylene

Question 50

❓ What are the uses of ethanol?

Answer 50

Antiseptics Fuels Alcoholic beverages Antidote for methanol poisoning Industrial processes (e.g., dyeing)

Question 51

❓ Why is methanol dangerous?

Answer 51

✅ It is highly toxic and can cause nausea, blindness, or death.

Question 52

❓ Why is methanol added to industrial ethanol?

Answer 52

✅ To prevent consumption (denaturation).

Question 53

❓ What is the functional group of ethers?

Answer 53

✅ Two hydrocarbon groups (-R and -R') connected by an oxygen atom (-O-).

Question 54

❓ How are ethers related to water?

Answer 54

✅ Ethers are like water but with both hydrogens replaced by organic groups.

Question 55

❓ How do ethers compare to alcohols?

Answer 55

✅ Less dense, less soluble, more volatile, and lower boiling points.

Question 56

❓ What are common uses of ethers?

Answer 56

Solvents (for fats, rubber, and volatile oils) Medical anesthetics Pharmaceuticals (e.g., codeine, a morphine derivative)

Question 57

❓ What is a common safety concern with ethers?

Answer 57

✅ Highly flammable, so they are often replaced by less flammable alternatives like nitrous oxide.

Question 58

❓ How is diethyl ether produced?

Answer 58

✅ Condensation reaction of ethanol (via dehydration).

Question 59

❓ How are aldehydes formed?

Answer 59

✅ By oxidation of alcohols.

Question 60

❓ What is an example of an aldehyde?

Answer 60

✅ Acetaldehyde – a toxic intermediate in alcohol metabolism.

Question 61

❓ What reaction can aldehydes undergo?

Answer 61

✅ Polymerization, where small molecules (monomers) join to form large macromolecules.

Question 62

❓ How do ketones differ from aldehydes?

Answer 62

✅ Ketones have a carbonyl group (C=O) within the carbon chain, while aldehydes have it at the end of the chain.

Question 63

❓ How are ketones produced?

Answer 63

✅ By oxidation of secondary alcohols.

Question 64

❓ What are common uses of ketones?

Answer 64

Solvents Manufacturing of explosives, textiles, and paints Important in lipid metabolism

Question 65

❓ Why do ketones accumulate in the body?

Answer 65

✅ In conditions like starvation or diabetes, leading to ketosis.

Question 66

❓ How are carboxylic acids formed?

Answer 66

✅ By further oxidation of alcohols.

Question 67

❓ What is a common example of a carboxylic acid?

Answer 67

✅ Acetic acid (vinegar component).

Question 68

❓ How is acetic acid produced naturally?

Answer 68

✅ During wine fermentation, if oxygen levels are not controlled.

Question 69

❓ What are amines?

Answer 69

✅ Organic compounds derived from ammonia (NH₃), where one or more hydrogens are replaced by organic groups.

Question 70

❓ How are amines classified?

Answer 70

Primary (one hydrogen replaced) Secondary (two hydrogens replaced) Tertiary (three hydrogens replaced)

Question 71

❓ How are amines further categorized?

Answer 71

Aliphatic amines (only aliphatic groups) Aromatic amines (at least one aromatic group)

Question 72

❓ What are the properties of amines?

Answer 72

✅ They behave as weak bases and form salts in the presence of acids.

Question 73

❓ What are catecholamines?

Answer 73

✅ Amines that act as neurotransmitters, including dopamine, epinephrine, and histamine.

Question 74

❓ How are esters formed?

Answer 74

✅ By a reaction between a carboxylic acid and an alcohol (esterification).

Question 75

❓ What is the general formula of esters?

Answer 75

✅ R-COO-R', where R can be hydrogen, alkyl, or aromatic, but R' can only be alkyl or aromatic.

Question 76

❓ What is ester hydrolysis?

Answer 76

✅ A reversible reaction where an ester reacts with water to form an alcohol and a carboxylic acid.

Question 77

❓ What is saponification?

Answer 77

✅ A reaction where an ester reacts with sodium hydroxide (NaOH) to form a soap (sodium salt).

Question 78

❓ What is an important industrial application of saponification?

Answer 78

✅ Production of sodium stearate (soap).

Question 79

❓ Why were chemical nomenclature rules created?

Answer 79

✅ To establish a universal system for naming chemical compounds, minimizing miscommunication.

Question 80

❓ Who created the most widely accepted nomenclature rules?

Answer 80

✅ The International Union of Pure and Applied Chemistry (IUPAC).

Question 81

❓ Are there common names that do not follow IUPAC rules?

Answer 81

✅ Yes, for example, citric acid.

Question 82

❓ What is the first step in naming hydrocarbons?

Answer 82

✅ Identify the longest continuous carbon chain (parent name).

Question 83

❓ How do you determine the longest chain in complex cases?

Answer 83

✅ Use trial and error to find the chain with the most carbons.

Question 84

❓ What are the rules for choosing the longest chain when there are multiple possibilities?

Answer 84

Follow these priorities in order: 1. Greatest number of branches 2. Lowest possible prefix numbers for branches 3. Greatest number of carbons in the smallest branch 4. Least branched structure

Question 85

❓ How are carbon atoms numbered in alkanes?

Answer 85

✅ Start numbering from the end closest to the first branch.

Question 86

❓ How are alkyl groups added to the name?

Answer 86

List them before the parent chain Include their position number Use prefixes (di-, tri-, tetra-) for multiple identical groups Separate numbers with commas and words with hyphens

Question 87

❓ How are branched groups listed?

Answer 87

✅ In alphabetical order, ignoring prefixes (e.g., ethyl before dimethyl).

Question 88

❓ How do you name alkenes and alkynes?

Answer 88

✅ Similar to alkanes, but you must specify double or triple bond locations.

Question 89

❓ How are multiple double or triple bonds indicated?

Answer 89

✅ Use di-, tri-, or tetra- before "ene" or "yne" (e.g., butadiene).

Question 90

❓ Where do you place numbers for double or triple bonds?

Answer 90

✅ Before the parent name, indicating the first carbon of the bond.

Question 91

❓ How are monosubstituted benzenes named?

Answer 91

✅ The substituent automatically gets position 1, so no number is needed.

Question 92

❓ How are positions assigned in disubstituted benzenes?

Answer 92

✅ Use: Ortho- (o-) for adjacent (1,2) positions Meta- (m-) for middle (1,3) positions Para- (p-) for opposite (1,4) positions

Question 93

❓ Can aromatic compounds have multiple substituents?

Answer 93

✅ Yes, but positions must be explicitly numbered.

Question 94

❓ What is a monofunctional compound?

Answer 94

✅ A compound with only one type of functional group.

Question 95

❓ How do functional groups affect naming?

Answer 95

✅ The functional group determines the suffix (e.g., -ol for alcohols, -one for ketones).

Question 96

❓ How do you indicate carbon positions in functional groups?

Answer 96

✅ Use numbers, following the same rules as for hydrocarbons.

Question 97

❓ Why is naming polyfunctional compounds difficult?

Answer 97

✅ They have multiple functional groups, making nomenclature complex even for experts.

Question 98

What is epoxidation?

Answer 98

This is a chemical reaction characterized by converting a double bond into epoxides. Epoxides are cyclic ethers in which the ether forms a three-atom ring involving two carbons and one oxygen.

Question 99

❓ What is the goal of studying organic reactions?

Answer 99

✅ To identify patterns, relationships, and trends that help predict reaction outcomes.

Question 100

❓ How does three-dimensional (3D) notation help in organic chemistry?

Answer 100

✅ It visualizes bonds spatially, aiding in reaction understanding.

Question 101

❓ What happens when a reagent (X-Y) is added to an alkene or alkyne?

Answer 101

✅ The double or triple bond breaks, and the reagent attaches to the carbon atoms.

Question 102

❓ What rule explains the addition pattern in these reactions?

Answer 102

✅ Markovnikov’s Rule: Electron-rich components attach to the carbon with more substituents. Electron-deficient components attach to the carbon with fewer substituents.

Question 103

❓ How does the addition of water (H₂O) to an alkene relate to Markovnikov’s rule?

Answer 103

✅ Water acts like HX, leading to the formation of alcohols instead of alkyl halides.

Question 104

❓ How can alkenes be tested for double or triple bonds?

Answer 104

✅ By adding halogens (Br₂ or Cl₂): If the reddish color disappears, the compound is unsaturated.

Question 105

❓ What is hydrogenation?

Answer 105

✅ The addition of hydrogen (H₂) to an alkene or alkyne, converting it into an alkane.

Question 106

❓ What does hydrogenation do to the oxidation state of carbon?

Answer 106

✅ It reduces carbon to its lowest oxidation state (-4).

Question 107

❓ What catalysts are commonly used in hydrogenation?

Answer 107

✅ Palladium (Pd) and Platinum (Pt) oxides.

Question 108

❓ Why are oxidation reactions more complex than reductions?

Answer 108

✅ They produce various intermediates or byproducts depending on catalysts and conditions.

Question 109

❓ What is the final oxidation state of an organic molecule?

Answer 109

✅ It forms an acid, incorporating the highest amount of oxygen.

Question 110

❓ What is epoxidation?

Answer 110

✅ A reaction where an alkene reacts to form an epoxide, later hydrolyzed into ethylene glycol (used in antifreeze).

Question 111

❓ What role does potassium permanganate (KMnO₄) play in oxidation?

Answer 111

✅ It oxidizes compounds into alcohols, ketones, or acids, depending on the reaction medium (acidic or basic).

Question 112

❓ What is Baeyer’s Test for Unsaturation?

Answer 112

✅ A test using Baeyer’s reagent (KMnO₄) to distinguish cyclopropane from cyclopropene.

Question 113

❓ What are polymers?

Answer 113

✅ Large molecules made from repeating monomers.

Question 114

❓ What are some common synthetic polymers?

Answer 114

✅ Polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), nylon, TPU, and PTFE.

Question 115

❓ What are natural (biological) polymers?

Answer 115

✅ Cellulose (sugar monomers) Proteins (amino acids) DNA (nucleotide monomers)

Question 116

❓ How are synthetic polymers made?

Answer 116

✅ By polymerizing alkenes using a catalyst.

Question 117

❓ What are the three steps of polymerization?

Answer 117

✅ Initiation – A free radical is created (e.g., benzoyl peroxide). Propagation – More monomers are added to the radical. Termination – The radical is consumed, stopping polymer growth.

Question 118

❓ What symbol is used to represent radical electron movement?

Answer 118

✅ Half-arrow (fishhook) notation.