Organic Chemistry

Question 1

Describe organic molecules

Answer 1

Molecules containing carbon atoms with the exception of carbon dioxide, carbon monoxide, diamond, graphite, carbonates, carbides and cyanides

Question 2

Hydrocarbon

Answer 2

A compound containing on,y carbon and hydrogen atoms

Question 3

Saturated compound

Answer 3

A compound in which all of the bonds between carbon atoms are single bonds

Question 4

Unsaturated compound

Answer 4

A compound in which there is at least one double and/or triple bond between carbon atoms

Question 5

Functional group

Answer 5

an atom or a group of atoms that form the centre of chemical activity in the molecule

Question 6

Homologous series

Answer 6

a series of similar compounds which have the same functional group and have the same general formula, in which each member differs from the previous one by a single CH2 unit

Question 7

What is the functional group of alkanes?

Answer 7

Only C-H and C-C bonds

Question 8

What is the functional group of alkenes?

Answer 8

Carbon-carbon double bond

Question 9

What is the functional group of haloalkanes?

Answer 9

Halogen atom bonded to a saturated C atom

Question 10

What is the functional group of alcohols?

Answer 10

Hydroxyl group bonded to a saturated C atom

Question 11

What is the functional group of carboxylic acids?

Answer 11

Carboxyl group

Question 12

What is the functional group of esters?

Answer 12

Ester group

Question 13

Describe a structural formula

Answer 13

Atoms are represented by their chemical symbols and lines are used to represent all the bonds between atoms.

Question 14

Describe a condensed structural formula

Answer 14

Represents the way in which atoms are bonded, but NOT ALL bond lines are shown.

Question 15

Describe a molecular formula

Answer 15

This is a chemical formula that indicates the type of atoms and the correct number of each in a molecule.

Question 16

Structural isomers

Answer 16

compounds having the same molecular formula but different structural formulae

Question 17

Describe chain isomers

Answer 17

Different type of chain structure, i.e. branching

Question 18

Describe positional isomers

Answer 18

Different positions of the same functional group or alkyl substituent on the parent chain

Question 19

Describe functional isomers

Answer 19

Different functional groups

Question 20

What is the intermolecular force of all hydrocarbon molecules

Answer 20

London intermolecular forces (molecules are non-polar)

Question 21

Why is a water bath used for gentle heating of organic reaction mixtures?

Answer 21

Many organic compounds are flammable

Question 22

What type of reaction is a combustion reaction?

Answer 22

Exothermic

Question 23

What are the general reaction types?

Answer 23

• combustion
• substitution
• addition
• elimination
• esterification

Question 24

What are the specific types of substitution reactions?

Answer 24

• Halogenation
• hydrolysis

Question 25

What is the conversion and reaction conditions for Halogenation (substitution)?

Answer 25

Conversion: alkanes to haloalkanes Reaction condition: in the presence of ultraviolet light or heat)

Question 26

What is the conversion and reaction conditions for Hydrolysis (substitution)?

Answer 26

Conversion: haloalkanes to alcohols Reaction conditions: heat under reflux in a dilute aqueous alkali solution

Question 27

If the reaction condition is “in the presence of ultraviolet light or heat”, what is the specific reaction?

Answer 27

Halogenation (substitution)

Question 28

If the reaction condition is “heat under reflux in a dilute aqueous alkali solution”, what is the specific reaction?

Answer 28

Hydrolysis

Question 29

What are the specific types of addition reactions?

Answer 29

- hydrogenation - Halogenation -hydrohalogenation - hydration

Question 30

What are the specific types of elimination reactions?

Answer 30

- dehydrohalogenation - dehydration - cracking of hydrocarbons

Question 31

What is the conversion and reaction conditions for Halogenation (addition)?

Answer 31

Conversion: addition of a Halogen (X2; X = Cl, Br) Reaction conditions: test for unsaturation

Question 32

What is the conversion and reaction conditions for Hydration (addition)?

Answer 32

Conversion: addition of H2O to any alkene Reaction condition: steam and a suitable catalyst)

Question 33

What is the conversion and reaction conditions for Hydrogenation (addition)?

Answer 33

Conversion: addition of H2 to any alkene Reaction condition: alkene dissolved in an organic solvent with a Pt, Pd or Ni caltalyst in a H2 atmosphere

Question 34

What is the conversion and reaction conditions for Hydrohalogenation (addition)?

Answer 34

Conversion: addition of HX to any alkene ( X = halogen) Reaction condition: no water may be present

Question 35

What is the test for unsaturation?

Answer 35

The rapid decolonisation of bromine water by an alkene at room temperature

Question 36

What is the purpose of the test for unsaturation?

Answer 36

To distinguish an alkene from an alkene (difference in Halogenation reactions)

Question 37

How is the the test for unsaturation able to distinguish alkenes from alkanes?

Answer 37

Since alkenes are more reactive than alkanes, addition reactions occur faster than substitution reactions

Question 38

If the reaction condition is “alkene dissolved in an organic solvent with a Pt, Pd or Ni catalyst in a H2 atmosphere “, what is the specific reaction?

Answer 38

Hydrogenation

Question 39

If the reaction condition is “test for unsaturation”, what is the specific reaction?

Answer 39

Halogenation (addition)

Question 40

If the reaction condition is “no water may be present”, what is the specific reaction?

Answer 40

Hydrohalogenation

Question 41

If the reaction condition is “steam and a suitable catalyst”, what is the specific reaction?

Answer 41

Hydration

Question 42

What is the conversion and reaction conditions for dehydrohalogenation (elimination)?

Answer 42

Conversion: elimination of HX from any haloalkane (X = halogen) Reaction condition : hot concentrated solution of NaOH or KOH in an ethanol solvent ie. in the absence of water; the amount of water produced in the second reaction is insufficient to cause hydrolysis

Question 43

What is the conversion and reaction conditions of dehydration (elimination)?

Answer 43

Conversion: elimination of H2O from any alcohol Reaction conditions: acid catalysed dehydration- heating of alcohol with an excess of concentrated H2SO4 or H3PO4

Question 44

If the reaction condition is “hot concentrated solution of NaOH or KOH in an ethanol solvent”, what is the specific reaction?

Answer 44

Dehydrohalogenation

Question 45

If the reaction condition is “heating of alcohol with an excess of concentrated H2SO4 or H3PO4”, what is the specific reaction?

Answer 45

Dehydration

Question 46

What is the cracking of hydrocarbons?

Answer 46

Breaking up large alkane molecules to form a mixture of smaller and more useful alkane and alkene molecules

Question 47

What are the reaction conditions for the cracking of hydrocarbons?

Answer 47

- thermal cracking : high pressures and temperatures without a catalyst - catalytic cracking : lower temperatures and pressures in the presence of a catalyst

Question 48

Are combustion reactions exothermic or endothermic?

Answer 48

Exothermic

Question 49

What is esterification?

Answer 49

An acid-catalysed reaction between an alcohol and a carboxylic acid that produces an ester and water

Question 50

What are the reaction conditions for esterification?

Answer 50

Acid catalyst and gentle heating

Question 51

What are two known products of the complete combustion of alkanes, alkenes and alcohols with excess oxygen?

Answer 51

Produce water (H2O) and carbon dioxide (CO2)