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8/12/2019 PEC140 SB12 Tutorial Answers
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PEC140 Introduction to Chemistry
STUDY BLOCK 1 Tutori!" #ns$ers
1.
#"coho" n!me Structure C"!ssi%ic!tion
propan-1-ol
OH
or simply
CH3CH2CH2OH
Primary (1o)
2-methylpentan-2-olCH3
CH2CH2
C
CH3
OH
CH3
Tertiary (3o)
cyclohexanolOH
OR
CH
CH2
CH2
CH2
CH2
CH2
OH
Secondary (2o)
-ethyl-3-methyloctan-3-ol
OH
Tertiary (3o)
2.
&!me Tol!ene (methyl"en#ene) Phenol (hydroxy"en#ene)
Structure
CH3 OH
'o"!r m!ss $2 % mol&1 $' % mol&1
Boi"in( )oint 111oC 12oC
Tol!ene is a non-polar hydrocar"onand the only possi"ility or intermolec!lar orces is
dispersion (ind!ced dipole-ind!ced dipole interactions). Phenol is polard!e to the presence
o the hydroxyl (OH) %ro!p and is a"le to participate in hydro%en "ondin% interactions. *sample o a compo!nd +ill "oil +hen eno!%h ener%y has "een added to o,ercome the
intermolec!lar interactions allo+in% molec!les to lea,e the "!l li!id and enter the %as
1
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phase. /ore ener%y is re!ired to o,ercome the intermolec!lar orces or phenol "eca!se
hydro%en "ondin% is a m!ch stron%er interaction than dispersion orces.
3. Phenol is expected to "e more sol!"le in +ater than tol!ene . 0ater molec!les are polar and
can interact +ith other polar molec!les. Phenol has a polar hydroxyl %ro!p that can
participate in hydro%en "ondin% interactions +ith +ater. The non-polar str!ct!re o tol!enedoes not allo+ or intermolec!lar interaction +ith +ater molec!les and it is less a"le to
dissol,e in +ater.
'.
C
OH
O
1/nO' H
1/nO' HCH2OH
C
H
O
C OH
H
H3C
CH3
1/nO' H
C
CH3
O
H3C
C OH
CH3
H3C
CH3
1/nO' H
4o reaction
5. *n e!ation or the acid catalysed reaction "et+een "!tanoic acid and propanol in the
ormation o an ester.
CH2CH2CH3
COH
O
3 CH3CH2CH2OH H
CH2CH2CH3
CO
O
H3CH2CH2C
The name o the ester that orms ispropyl "!tanoate.
.
4
CH3
H
2oamine
CH3 CH2
CH2 C
4H2
CH3
CH3
1oamine
2-methylpentan-2-amine
4
CH3
CH3
3oamine
2
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CH
CH3CH2CH2
CH3
4H2
1oamine
pentan-2-amine
4H2
1oamine
cyclopentanamine
4H2
1oamine
2-methylpentan-1-amine
6.
&!me *niline (amino"en#ene) Phenol (hydroxy"en#ene)
Structure
4H2 OH
*!ter so"u+i"ity !t 0oC 3. %7188 m9 .3 %7188 m9
:oth compo!nds ha,e a de%ree o +ater sol!"ility d!e to the presence o polar amine and
hydroxyl %ro!ps. *mine %ro!ps and hydroxyl %ro!ps are capa"le o hydro%en "ondin%
interactions +ith +ater molec!les d!e to the presence o polar 4H and OH "onds
respecti,ely. The reason +hy phenol is more sol!"le in +ater is d!e to the %reater
electrone%ati,ity o oxy%en compared to nitro%en.The OH "onds are more polar and the
hydro%en "ondin% interaction +ith +ater is %reater.
.
OH
O
;rom let to ri%ht< car"oxylic acidand alene
Oleic acid & a atty acid that is a ma=or component o oli,e oil. Can yo! explain +hy
it is no+n as an !nsat!rated atty acid>
4CH3
OH
CH3
H
;rom let to ri%ht
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C
CHOH
OH3C
H3C
;rom let to ri%ht< ether"en#ene rin%7aromatic rin% alcohol (3o) alyne
/estranol & a component o oral contracepti,es
O
Cl
C
CH
:r
OH
;rom let to ri%ht< alcohol (2o) alene
ether halo%en(:r) halo%en(Cl) alene
alyne
O
O
CH3
OH CH2
O
H3C
;rom let to ri%ht< alene etone alcohol
(2o) alene ester
* toxic compo!nd synthesised "y the sea
hare to eep predators a+ayThe anticancer dr!% AhelenalinB
$.
Structure IUP#C &!me
OH
O
3-ethyl-2-methylhexanoic acid
C CCH3 C
O
CH3
pent-3-yn-2-one
'
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CH2
CCH3O
O
CH2CH3
ethyl propanoate
CH2
CH2CH2
CH
O
:r '-"romo"!tanal
'-ethyl-25-dimethylheptane
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