Organic Chemistry

Question 1

What is organic chemistry?

Answer 1

The study of carbon-based compounds and their reactions.

Question 2

What are hydrocarbons?

Answer 2

Compounds made of only carbon and hydrogen

Question 3

What are functional groups?

Answer 3

Specific atom arrangements that define chemical properties, like hydroxyl (-OH) and carboxyl (-COOH).

Question 4

What is the difference between alkanes, alkenes and alkynes?

Answer 4

Alkanes have single bonds, alkenes have double bonds, and alkynes have triple bonds.

Question 5

What is isomerism?

Answer 5

Molecules with the same formula but different structures.

Question 6

What is a polymer?

Answer 6

Large molecules made of repeating smaller units (monomers).

Question 7

What is the role of catalysts in organic reactions?

Answer 7

They speed up reactions without being consumed.

Question 8

What are aromatic compounds?

Answer 8

Molecules with conjugated ring structures, like benzene.

Question 9

What is an electrophile?

Answer 9

A species that accepts electrons in a reaction.

Question 10

What is esterification?

Answer 10

A reaction between an alcohol and an acid to form an ester.

Question 11

What is an alkyl group?

Answer 11

A hydrocarbon chain attached to a molecule.

Question 12

What are alcohols?

Answer 12

Organic compounds containing an -OH (hydroxyl) group.

Question 13

What is the difference between ketones and aldehydes?

Answer 13

Aldehydes have a carbonyl group at the end of a chain, while ketones have it in the middle.

Question 14

What are carboxylic acids?

Answer 14

Organic acids with a -COOH functional group.

Question 15

What is a nucleophile?

Answer 15

A species that donates electrons in a reaction.

Question 16

What is a condensation reaction?

Answer 16

A reaction where two molecules combine, releasing water.

Question 17

What is cracking in organic chemistry?

Answer 17

Breaking down large hydrocarbons into smaller ones.

Question 18

What are amines?

Answer 18

Organic compounds containing nitrogen (-NH₂ group).

Question 19

How do esters smell?

Answer 19

They often have fruity or sweet aromas.

Question 20

What is the difference between addition and substitution reactions?

Answer 20

Addition reactions add atoms to a molecule, while substitution replaces one atom with another.

Question 21

What is the hybridization of the carbon atom in methane (CH₄)?

Answer 21

\sp^3 \ hybridization.

Question 22

Why are ethers less reactive than alcohols?

Answer 22

Ethers lack the reactive hydroxyl (-OH) group.

Question 23

What is the IUPAC name for acetone?

Answer 23

Propanone

Question 24

How does the presence of a nitro group affect the reactivity of benzene?

Answer 24

It deactivates benzene, making it less reactive in electrophilic substitution.

Question 25

What is the functional group in amides?

Answer 25

\-CONH_2 \.

Question 26

Why are alkyl halides used in nucleophilic substitution reactions?

Answer 26

The halogen atom is a good leaving group.

Question 27

What is Markovnikov's rule in addition reactions?

Answer 27

The hydrogen atom adds to the carbon with more hydrogens, and the other group adds to the carbon with fewer hydrogens.

Question 28

What is the product of the oxidation of a primary alcohol?

Answer 28

An aldehyde, and further oxidation produces a carboxylic acid.

Question 29

Why are aromatic compounds unusually stable?

Answer 29

They have delocalized \\\pi \-electrons forming a resonance structure.

Question 30

What is the difference between cis and trans isomers?

Answer 30

Cis isomers have groups on the same side; trans isomers have groups on opposite sides.

Question 31

What is the role of Grignard reagents in organic synthesis?

Answer 31

They act as nucleophiles to form carbon-carbon bonds.

Question 32

What is the functional group in thiols?

Answer 32

\-SH \.

Question 33

How does the inductive effect influence acidity in organic compounds?

Answer 33

Electron-withdrawing groups increase acidity by stabilizing the conjugate base.

Question 34

What is the product of the reaction between an acid chloride and an alcohol?

Answer 34

An ester

Question 35

Why are alkynes more acidic than alkenes and alkanes?

Answer 35

The \sp \ hybridized carbon in alkynes holds electrons closer, stabilizing the conjugate base.

Question 36

What is the product of the reaction between a ketone and hydrogen cyanide (HCN)?

Answer 36

A cyanohydrin.

Question 37

Why are phenols more acidic than alcohols?

Answer 37

The phenoxide ion is stabilized by resonance in phenols.

Question 38

What is the functional group in aldehydes?

Answer 38

\-CHO \.

Question 39

How does the presence of a double bond affect the geometry of alkenes?

Answer 39

Alkenes have a planar geometry around the double bond due to \sp^2 \ hybridization.

Question 40

What is Hybridization?

Answer 40

Hybridization is the mixing of atomic orbitals to form new hybrid orbitals, which determines molecular shape and bonding properties.

Question 41

Why is using a hot plate with a loose-fitting cover safer than using a Bunsen burner to heat organic liquids when measuring their boiling points?

Answer 41

A hot plate is safer than a Bunsen burner because it reduces the risk of fire when heating flammable organic liquids and provides better temperature control.

Question 42

What is crude oil, and how is it formed?

Answer 42

Crude oil is a fossil fuel formed from ancient organic matter buried and subjected to heat and pressure over millions of years.

Question 43

What are the main components of crude oil?

Answer 43

Mostly hydrocarbons, with small amounts of sulfur, nitrogen, and oxygen compounds.

Question 44

How does fractional distillation separate crude oil into different products?

Answer 44

It heats crude oil, separating components based on boiling points into fuels like petrol, diesel, and kerosene.

Question 45

What are some common fuels derived from crude oil, and how are they used?

Answer 45

Petrol (cars), diesel (trucks), kerosene (jet fuel), and LPG (cooking, heating).

Question 46

What environmental concerns are associated with crude oil extraction and use?

Answer 46

Air pollution, greenhouse gas emissions, oil spills, and habitat destruction.

Question 47

How do oil spills impact marine ecosystems, and what cleanup methods exist?

Answer 47

They harm wildlife and ecosystems; cleanup methods include skimming, dispersants, and bioremediation.

Question 48

What is the difference between conventional and unconventional crude oil sources?

Answer 48

Conventional oil is easily extracted; unconventional (shale oil, tar sands) requires specialized techniques.

Question 49

How does crude oil refining work, and what products are obtained from it?

Answer 49

Refining separates and chemically processes crude oil into fuels, lubricants, and petrochemicals.

Question 50

What role does OPEC play in the global crude oil market?

Answer 50

OPEC regulates oil production among member countries to influence prices and supply.

Question 51

What alternatives to crude oil are being developed to reduce dependence on fossil fuels?

Answer 51

Renewable energy sources like solar, wind, biofuels, and hydrogen fuel.

Question 52

What is the molecular formula of butane?

Answer 52

C₄H₁₀

Question 53

How does the structural formula of propane differ from butane?

Answer 53

Propane has three carbon atoms (C₃H₈), while butane has four (C₄H₁₀).

Question 54

What is the molecular formula of methane?

Answer 54

CH₄

Question 55

What is the molecular formula of ethane?

Answer 55

C₂H₆

Question 56

How does the number of carbon atoms affect boiling points of methane, ethane, propane, and butane?

Answer 56

More carbon atoms increase the boiling point (methane < ethane < propane < butane).

Question 57

Why are methane, ethane, propane, and butane considered alkanes?

Answer 57

They only contain single bonds and follow the CₙH₂ₙ₊₂ formula.

Question 58

What is the primary use of methane and ethane?

Answer 58

Methane is used in natural gas for heating, ethane is a feedstock for plastics.

Question 59

Why is propane stored as a liquid in gas cylinders?

Answer 59

It liquefies under moderate pressure, making transport and storage easier.

Question 60

What are the products of complete combustion of methane, ethane, propane, and butane?

Answer 60

Carbon dioxide (CO₂) and water (H₂O).

Question 61

Which alkane is most commonly used in lighters?

Answer 61

Butane, due to its liquid state at room temperature.

Question 62

How do methane and ethane contribute to greenhouse gases?

Answer 62

Methane is a potent greenhouse gas, ethane contributes to air pollution when leaked.

Question 63

What common fuels are derived from propane and butane?

Answer 63

LPG (Liquefied Petroleum Gas), used for heating and cooking.

Question 64

Describe and explain how crude oil is separated into fractions by fractional distillation?

Answer 64

Crude oil is heated, vaporized, and enters a fractionating column. Larger hydrocarbons condense lower, smaller ones rise higher. Fractions like bitumen, diesel, kerosene, petrol, and gases are collected by boiling points.