organic chem terms

Question 1

What does the term ‘Aliphatic’ refer to?

Answer 1

Organic compounds containing C chains and branches.

Aliphatic compounds are typically saturated or unsaturated hydrocarbons.

Question 2

What characterizes ‘Aromatic’ compounds?

Answer 2

Organic compounds containing one or more benzene ring(s).

Aromatic compounds are known for their stability and unique chemical properties due to resonance.

Question 3

Define ‘Cyclic’ in the context of organic chemistry.

Answer 3

Organic compounds containing C rings (not aromatic rings), also called alicyclic.

Cyclic compounds can be saturated or unsaturated.

Question 4

What is a ‘Functional group’?

Answer 4

The atom or group of atoms that is responsible for most of the chemical reactions of a molecule.

Functional groups determine the properties and reactions of organic compounds.

Question 5

What is a ‘Homologous series’?

Answer 5

A family of compounds with the same general formula and similar chemical properties. Each member differs by the addition of a CH group and there is a gradual change in physical properties.

Examples include alkanes, alkenes, and alkynes.

Question 6

What is a ‘Hydrocarbon’?

Answer 6

Molecule containing hydrogen and carbon only.

Hydrocarbons can be aliphatic or aromatic.

Question 7

What does ‘Organic chemistry’ study?

Answer 7

Study of compounds containing carbon.

Organic chemistry encompasses a wide variety of compounds, including those with functional groups.

Question 8

What defines a ‘Saturated’ molecule?

Answer 8

Molecule containing no double bonds.

Saturated compounds have maximum hydrogen atoms attached to their carbon atoms.

Question 9

What are ‘Stereoisomers’?

Answer 9

Molecules with the same molecular and structural formulae but a different spatial arrangement of atoms.

This includes geometric and optical isomers.

Question 10

What are ‘Geometric isomers’?

Answer 10

Type of stereoisomerism: molecules which have different arrangement of groups around C=C.

Geometric isomers include cis and trans configurations.

Question 11

Define ‘Structural isomers’.

Answer 11

Molecules with the same molecular formula but different structures.

Structural isomers can have different physical and chemical properties.

Question 12

What are ‘Chain isomers’?

Answer 12

Type of structural isomerism: Structural isomers that differ by having a different carbon chain.

Chain isomers can vary in the length and branching of the carbon chain.

Question 13

Define ‘Position isomers’.

Answer 13

Type of structural isomerism: Structural isomers that differ by having the functional group in a different position.

Position isomers can exhibit different reactivity and properties.

Question 14

What are ‘Functional group isomers’?

Answer 14

Type of structural isomerism: Structural isomers that differ by having a different functional group.

Functional group isomers can have significantly different chemical behaviors.

Question 15

What does ‘Unsaturated’ mean in organic chemistry?

Answer 15

Molecule containing double bond(s).

Unsaturated compounds include alkenes and alkynes, which can undergo addition reactions.

Question 16

What is an addition reaction?

Answer 16

Reaction where a molecule joins to an unsaturated molecule to produce a saturated molecule

This type of reaction is common in organic chemistry, particularly with alkenes and alkynes.

Question 17

What defines an aromatic compound?

Answer 17

Contain a substance called a benzene ring (C6H6)

Aromatic compounds are known for their stability and unique chemical properties due to resonance.

Question 18

What is a biofuel?

Answer 18

A fuel produced from renewable biological resources

Examples include ethanol and biodiesel, derived from crops and waste materials.

Question 19

What is bond fission?

Answer 19

Breaking a covalent bond

This process is essential in chemical reactions where bonds are formed or broken.

Question 20

What is a carbon footprint?

Answer 20

A measure of the impact our activities have on the environment in terms of the amount of greenhouse gases we produce

It is typically expressed in equivalent tons of CO2.

Question 21

What does carbon neutral mean?

Answer 21

An activity that has no net carbon dioxide emissions to the atmosphere

This can be achieved by balancing emitted CO2 with an equivalent amount sequestered or offset.

Question 22

What is climate change?

Answer 22

Change to the Earth’s climate caused by pollutants

This includes changes in temperature, precipitation patterns, and extreme weather events.

Question 23

What is a catalyst?

Answer 23

A substance that speeds up a chemical reaction but is chemically unchanged at the end

Catalysts lower the activation energy needed for reactions to occur.

Question 24

What is complete combustion?

Answer 24

When all the elements in a combustion reaction are fully oxidised to CO2 and H2O

This process releases the maximum amount of energy from the fuel.

Question 25

What is cracking?

Answer 25

Using either heat or a zeolite catalyst to break long chain alkanes into shorter chain alkanes and an alkene ## Footnote This process is important in the petroleum industry for converting heavy fractions into more useful products.

Question 26

What does exothermic mean?

Answer 26

A reaction that gives out (exo) heat (thermic) ## Footnote Exothermic reactions are characterized by a temperature increase in the surroundings.

Question 27

What are flue gases?

Answer 27

Gases that leave a chimney (flue) ## Footnote These gases often contain pollutants from combustion processes.

Question 28

What are fossil fuels?

Answer 28

Non-renewable fuels made from the action of heat and pressure on dead plants and animals ## Footnote Examples include coal, oil, and natural gas.

Question 29

What is a fraction in chemistry?

Answer 29

A group of hydrocarbons with similar boiling points ## Footnote Fractions are obtained through processes like fractional distillation.

Question 30

What is fractional distillation?

Answer 30

A method of separating the hydrocarbons in crude oils by their boiling point ## Footnote This technique is widely used in the petroleum refining industry.

Question 31

What is a free radical?

Answer 31

Species with an unpaired electron ## Footnote Free radicals are highly reactive and can initiate chain reactions in organic chemistry.

Question 32

What is a functional group?

Answer 32

The atom or group of atoms that is responsible for most of the chemical reactions of a molecule ## Footnote Examples include hydroxyl (-OH), carboxyl (-COOH), and amino (-NH2) groups.

Question 33

What is global dimming?

Answer 33

A decrease in the amount of sunlight reaching the earth's surface caused by atmospheric pollutants ## Footnote This phenomenon can influence climate and weather patterns.

Question 34

What is global warming?

Answer 34

A heating effect resulting in a gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, CFCs, and other pollutants ## Footnote This issue is central to discussions on climate change and environmental policy.

Question 35

What is the greenhouse effect?

Answer 35

A warming of the atmosphere caused by greenhouse gases ## Footnote This effect is necessary for life, but excessive greenhouse gases lead to climate change.

Question 36

What are greenhouse gases?

Answer 36

A gas that absorbs shortwave solar radiation and reemits it as long wave IR (heat) radiation ## Footnote Gases include CO2, hydrocarbons, CH4, H2O, CFCs.

Question 37

What is a homologous series?

Answer 37

A family of compounds with the same general formula and similar chemical properties ## Footnote In a series, each member differs by the addition of a CH2 group.

Question 38

What is a hydrocarbon?

Answer 38

Molecule containing hydrogen and carbon only ## Footnote Hydrocarbons can be saturated (alkanes) or unsaturated (alkenes and alkynes).

Question 39

What is incomplete combustion?

Answer 39

When not all the elements in a combustion reaction are fully oxidized, e.g. C or CO is produced by combustion ## Footnote This process releases less energy and produces harmful pollutants.

Question 40

What are intermolecular forces?

Answer 40

Weak forces between molecules ## Footnote These forces influence boiling points, melting points, and solubility of compounds.

Question 41

What is the molecular formula?

Answer 41

Formula that gives the actual number of atoms of each element in one molecule. ## Footnote It represents the composition of a molecule in terms of the number of each type of atom present.

Question 42

What does oxidation refer to in chemistry?

Answer 42

Adding oxygen to a substance, e.g. combustion. ## Footnote Oxidation involves the loss of electrons or an increase in oxidation state.

Question 43

What is a reaction mechanism?

Answer 43

A series of steps in a chemical reaction. ## Footnote It details how reactants are transformed into products at a molecular level.

Question 44

What are structural isomers?

Answer 44

Molecules with the same molecular formula but different structures. ## Footnote These isomers have different physical and chemical properties despite having the same number of atoms.

Question 45

Define substitution reaction.

Answer 45

Reaction where an atom/group replaces another atom/group. ## Footnote This type of reaction is common in organic chemistry.

Question 46

What does thermal mean in a chemical context?

Answer 46

Using heat in a process. ## Footnote Thermal processes can influence reaction rates and outcomes.

Question 47

What are Van der Waals forces?

Answer 47

Electron movement in first molecule gives rise to a temporary dipole. This induces a dipole in another molecule which gives rise to a temporary attraction in adjacent molecules. ## Footnote These forces are weak intermolecular forces that play a crucial role in molecular interactions.

Question 48

What is zeolite?

Answer 48

A naturally occurring aluminium silicate (clay) based compound that has a honeycomb cage-like structure. ## Footnote Zeolites are used in various applications including catalysis and ion-exchange.