1.1 Structure And Formulae

Question 1

2 types of organic compounds

Answer 1

1. aliphatic
2. aromatic

Question 2

aliphatic organic componds

Answer 2

the carbon atomsare bonded together in straight chains or straight chains and branched chains

Question 3

aromatic organic compounds

Answer 3

the carbon atoms are bonded together in rins and contain the benzene ring in the structure

Question 4

hydrocarbon prefixes

Answer 4

1- meth
2- eth
3- prop
4- but
5- pent
6- hex
7- hept
8- oct
9- non
10- dec

Question 5

UPAC rules for naming compounds

Answer 5

1. the name will contain a prefix which tells the largest number of continuously linked C atoms containing the functional group
2. the C atoms of the longest chain are numbered o indicate the positions of the attached groups (stas from end which gives smaller no.)
3. the name of the attached group is placed in front of the prefix (hypen separates position and name of attached group)
4. numbers are separated by commas/ numbers are separated from words by hyphens
5. whenever there are several attached groups, their names are placed in alphabetical order before the prefix
6. the C atoms of the longest chain are also numbered to indicate the positin of the functional group (placed before prefix and name of functional group)
7. the positioning of the functional group takes precedence over attached group (numbering starts from end which gives functional group the smallest number)

Question 6

what is an isomer

Answer 6

compounds which have the same molecular formula but different structural formula

Question 7

2 types of isomers

Answer 7

1. structural isomers
2. steroisomers

Question 8

what are structural isomers

Answer 8

isomers which differ in how the atoms are bonded together in a molecule of the compound
(differ in which atom is bonded to which)

Question 9

3 types of structural isomers

Answer 9

1. branch chain
2. positional
3. functional group

Question 10

branched chain isomers

Answer 10

they differ only in the number of C atoms in a straight chain and number of branches

Question 11

positional isomers

Answer 11

differ only in the positions of the attached groups or the functional group on the same number of continuously linked C atoms

Question 12

what are functional group isomers?

Answer 12

they belong to different homologous series and have different functional groups

Question 13

which groups of homologous series are functional group isomers found

Answer 13

carboxylic acids and esters
alcohols and ethers
aldehydes and ketones

Question 14

what are stereoisomers

Answer 14

they differ in their spacial arrangement of atoms or groups of atoms around carbon atoms

they do not differ in which atom is bonded to which

Question 15

2 types of stereoisomers

Answer 15

geometric/ cis-trans
optical

Question 16

what are cis-trans isomers

Answer 16

they differ in the arrangement of atoms or groups of atoms arounda pair of double bonded C atoms

Question 17

what is a cis-isomer

Answer 17

the isomer with the pair of identical groups on the same side of the double bond

Question 18

what is a trans isomer

Answer 18

isomer in which the pair of identical groups are on opposite sides of the double bond

Question 19

what are optical isomers

Answer 19

they differ only in the direction they rotate in the plane of polarized light

Question 20

what is the plus isomer

Answer 20

the isomer that rotates the light in a clockwise direction

Question 21

what is the minus isomer

Answer 21

the isomer that rotates the light in an anticlockwise direction

Question 22

what is the condition for optical isomerism

Answer 22

compound with a chiral centre/ asymmetric C atom which bonds to 4 different atoms or groups of atoms

Question 23

what is a racemate/ racemix mixture

Answer 23

it consists of equimolar quantities of plus or minus isomers
any attempt to make an optically active compund results in the formation of a racemate mixture

Question 24

how can a racemate mixture be separated from individual isomers

Answer 24

through resolution

Question 25

characteristics of skeletal structure

Answer 25

1. only bonds between C atoms are shown
2. no H atoms are shown on the C atoms
3. other atoms and groups (Br, Cl, I, OH, COOH, NH2) are shown

Question 26

what is catenation?

Answer 26

the ability of cabon atoms to form chains by joining

Question 27

what is tetravalency?

Answer 27

when the atom has four valence electrons in its outer principal quantum shell and it forms four bonds with other atoms

Question 28

what is resonance?

Answer 28

a way of describing delocalized electrons within certain molecule or polyatomic ions where boning caot be expressed by a singe Lewis structure

Question 29

what is hybridization?

Answer 29

the process of mixing atomic orbitals

Question 30

what is a homologus series?

Answer 30

a group of organic compounds with the same functionl group in which each successive member increases by a CH2 unit

Question 31

empirical formula

Answer 31

formula showing simplest ratio of atoms of each element in a compound

Question 32

molecular formula

Answer 32

a formla showin the actual number of atoms of each element present in a molecule of a compound

Question 33

structural formula

Answer 33

formula showing the arrangement of atoms in a cule in a simplified form