14 - introduction to organic chemistry

Question 1

ways of representing organic molecules:

Answer 1

. empirical formula
. molecular formula
. structural formula
. displayed formula
. skeletal formula

Question 2

empirical formula

Answer 2

simplest ratio of the different types of atoms present in the molecule

Question 3

molecular formula

Answer 3

shows actual numbers of each type of atom in a molecule

Question 4

structural formula

Answer 4

the formula that shows how many, and the symbols of, atoms bonded to each carbon atom in an organic molecule

shows double bonds

Question 5

displayed formula

Answer 5

a 2D representation of an organic molecule, showing all its atoms (by symbols) and their bonds

Question 6

skeletal formula

Answer 6

simplified displayed formula with all C and H atoms and C-H bonds removed

Question 7

homologous series

Answer 7

a group of organic compounds having the same functional group, the same general formula, and similar chemical properties

Question 8

functional group

Answer 8

an atom or group of atoms in an organic molecule which determines the characteristic chemical reactions

Question 9

general formula

Answer 9

a formula that represents a homologous series of compounds using letters and numbers

Question 10

aliphatic

Answer 10

straight or branched chain organic compounds, and also include cyclic organic compounds that do not contain benzene rings

Question 11

alkenes general formula

Answer 11

CnH2n

Question 12

halogenoalkenes general formula

Answer 12

CnH2n+1X

X = F, Cl, Br, I
chloromethane (CH3Cl)

Question 13

alcohols general formula

Answer 13

CnH2n+1OH
methanol (CH3OH)

Question 14

aldehydes general formula

Answer 14

CnHn+1CHO
ethanal (CH3CHO)

Question 15

ketones general formula

Answer 15

CnH2n+1COCmH2m+1
propanone (CH3COCH3)

Question 16

carboxylic acids general formula

Answer 16

CnH2n+1COOH
ethanoic acid (CH3COOH)

Question 17

esters general formula

Answer 17

CnH2n+1COOCmH2m+1
propyl ethanoate (CH3COOC3H7)

Question 18

amines general formula

Answer 18

CnH2n+1NH2
methylamine (CH3NH2)

Question 19

nitriles general formula

Answer 19

CnH2n+1CN
ethanenitrile (CH3CN)

Question 20

aryl compound

Answer 20

have a benzene ring

Question 21

benzene

Answer 21

C6H6 (circle inside hexagon)

Question 22

single covalent bonds

Answer 22

a bond made up of a pair of electrons shared between two atoms

Question 23

sigma bonds

Answer 23

a single covalent bond formed by thr end on overlap of atomic orbitals

Question 24

pi bond

Answer 24

covalent bond formedc by sideways overlap of p and p OR p and d atomic orbitals

Question 25

why do the two lobes making up a pi bond lie above and below the plane of atoms

Answer 25

to maximise overlap

Question 26

triple bond has how many pi bonds

Answer 26

2

Question 27

structural isomerism

Answer 27

compounds with the same molecular formula but different structural formulae

Question 28

types of structural isomerism

Answer 28

. position isomerism . functional group isomerism . chain isomerism

Question 29

position isomerism

Answer 29

functional group location varies

Question 30

functional group isomerism

Answer 30

different functional groups

Question 31

chain isomerism

Answer 31

different carbon skeleton

Question 32

stereoisomers

Answer 32

compounds whose molecules have the same atoms bonded to each other in the same way, butg with a different arrangement of atoms in space so that the molecules cannot be superimposed by each other

Question 33

types of stereoisomers

Answer 33

. geometrical (cis/trans) isomerism . optical isomerism

Question 34

geometrical (cis/trans) isomerism

Answer 34

. no free rotation about a CC double bond . cis = Br aoms on same side . trans = Br positioned across double bond . have different chemical properties (reaction rates) . possible in substituted cyclic compounds

Question 35

optical isomerism

Answer 35

. also called enantiomers (pair of optically active molecules whose mirror images cannot be superimposed) . C atoms at enantiomers' center is called chiral center . pair of optical rotates a plane polarised light my same magnitude, in opposite directions

Question 36

chiral center

Answer 36

a carbon atom with the four different atoms or group of atoms attached, allows optical isomers to exist

Question 37

do symmetrical substituted cyclic molecules have a chiral center

Answer 37

no

Question 38

reaction mechanism

Answer 38

the series of steps that take place in the course of the overall reaction

Question 39

ways in which a covalent bonds can break

Answer 39

. homolytic fission . heterolytic fission

Question 40

homolytic fission

Answer 40

. both atoms get one electron from the shared covalent pair . make free radicals (shown with a dot) . free radical reaction occurs

Question 41

free radical reaction

Answer 41

. initiation : free radicals formed . propagation : steps regenerating more free radicals . termination : 2 free radicals meet and form a product molecule

Question 42

heterolytic fission

Answer 42

. uneven breaking of a covalent bond . more electrongative atom grakesxc both electrons . forms ions . draw arrow from bond to negative

Question 43

carbocation

Answer 43

an alkyl group with a single positive charge on one of its carbon atoms, formed in reaction mechanisms types: - primary - secondary - tertiary (most stable)

Question 44

inductive effect

Answer 44

the uneven sharing of electrons along a covalent bond, electron donating species are said to have a positive inducing effect

Question 45

more alkyl groups =? stable

Answer 45

more stable

Question 46

more alkyl groups =? stable

Answer 46

more stable

Question 47

electrophile

Answer 47

a species in organic chemistry that cafbm ct as an electron pair acceptor

Question 48

nucleophiles

Answer 48

species that can act as a donor of a pair of electrons

Question 49

types of organic reactions

Answer 49

. addition . elimination . condesnation . substitution reactions (free radical sub) . oxidation . reduction

Question 50

addition reactions

Answer 50

an organic reaction in which two or more molecules combine to give a single product molecule

Question 51

elimination reaction

Answer 51

a reaction in which a small molecule (water, HCl) is removed from an organic molecule

Question 52

condensation reaction

Answer 52

a reaction in which two organic molecules join together and in the process, eliminate a small molecule

Question 53

substitution reaction

Answer 53

a reaction that involve the replacement of one atom or group of atoms, by another