7. HHoommoollooggoouuss sseerriieess
series of compounds of similar properties whose molecular
formula differ by CH2 between adjacent members of the series.
HHoommoollooggoouuss sseerriieess FFoorrmmuullaa
AAllkkaanneess CCnnHH22nn++22
AAllkkeenneess CCnn HH22nn
AAllkkyynneess CCnn HH22nn--22
AAllccoohhoollss CCnn HH22nn++11 OOHH
AAllkkyyll hhaalliiddeess CCnn HH22nn++11 (( XX ((XX== FF,, CCll,, BBrr,, II
AAllddeehhyyddeess CCnn HH22nn++11CCHH OO
KKeettoonneess CC nnHH22nn CCOO
CCaarrbbooxxyylliicc aacciiddss CCnn HH22nn++11 CCOO22 HH
AAmmiiddeess CCnn HH22nn++11 CCOONNHH22
AAmmiinneess CCHHNNHHA
8. HHoommoollooggoouuss sseerriieess
The members show regular changes in properties
nn 22nn++22 MMoolleeccuullaarr
ffoorrmmuullaa
NNaammee
11 44 CCHH44 MMeetthhaannee
22 66 CC22 HH66 EEtthhaannee
33 88 CC33 HH88 PPrrooppaannee
44 1100 CC44 HH1100 BBuuttaannee
55 1122 CC55 HH1122 PPeennttaannee
66 1144 CC66 HH1144 HHeexxaannee
77 1166 CC77 HH1166 HHeeppttaannee
88 1188 CC88 HH1188 OOccttaannee
99 2200 CC99 HH2200 NNoonnaannee
1100 2222 CC1100 HH2222 DDeeccaannee
As the # C-atoms ↑:
reactivity ↓
mp ↑
bp ↑
d ↑
solubility ↓
(The first 10 members of the alkanes (CnH2n+2
9. An atom or aa ggrroouupp ooff aattoommss wwhhiicchh iimmppaarrtt
cchhaarraacctteerriissttiiccss pprrooppeerrttiieess ttoo aa ccoommppoouunndd
iiss ccaalllleedd FFuunnccttiioonnaall ggrroouupp..
10.
11. HHyyddrrooccaarrbboonnss
Type of bonds
Saturated hydrocarbons Unsaturated hydrocarbons
Single bond Double bond Triple bond
Alkanes
Substitution reaction Addition reaction
12. WWhhiicchh ooff tthhee ffoolllloowwiinngg ccoommppoouunnddss iiss
ssaattuurraatteedd aanndd wwhhiicchh iiss uunnssaattuurraatteedd??
H2C CH
C CH
H3C
CH3
H2
C C CH3
CH3
HC CH
H2C CH
H2
C CH3
13. CChheemmiiccaall ffoorrmmuullaa
Molecular formula
Gives the numbers of
each atom in a molecule
Structural formula
Shows, in 2-dimensions,
exactly how the atoms
are bonded to each other
Ethane C2H6
H
H3C CH3 C C
H
H
H
H
H
=
14. Q. Write down the molecular aanndd ssttrruuccttuurraall ffoorrmmuullaa ooff::
MMeetthhaannee
EEtthhaannee
PPrrooppaannee
Molecular formula Structural formula
H
H
C C
H
H
H
H
H
Chemical formula
C2H6
H
H
H
C3H8 H
C C C
H
H H
H
CH4 C H
H
H
16. IISSOOMMEERRIISSMM
Organic Compounds can exist in different
forms with the same molecular formula but
different structural formulae.
SSTTRRUUCCTTUURRAALL
-- CChhaaiinn
- PPoossiittiioonnaall
- FFuunnccttiioonnaall
SSTTEERREEOO
- GGeeoommeettrriiccaall
- OOppttiiccaall
19. How many structural isomers does pentane, C5H12, have?
H H H H H
C C C C C
H
H H H H H
H
H CH3 H H
C C C C
H
H H H H
H
H CH3 H
C C C
H
H H
H
CH3
n-pentane
2-methylbutane
2,2-dimethylpropane
24.2
20. EExxaammpplleess
Molecular formula Structural formula
H
H
H
C C C
H
H H
H
H
C
H
H
H
H
H
C C C
H
H
C
H
H
H
H
H
Isomerism
Butane C4H10
n-butane
2-methyl propane
31. TTYYPPEESS OOFF OOPPTTIICCAALL AACCTTIIVVIITTYY
Dextrorotatory
Rotates the plane of plane-polarized light
to the right. Represented by (+)-
Levorotatory
Rotates the plane of plane-polarized light
towards left. Represented by (-)-