Heep Woh College
Form 5 Chemistry Assignment 2
Chapter 24
Fossil Fuels (Part I)
Suggested Answers
1. (a) 2-chloro-3-methylbutane (b) 2-methylbut-2-ene
(c) buta-1,3-diene-1,4-diol (d) 1-bromo-2,2-dichloropropane
(e) 1-bromopropan-2-ol 1 mark
each 1x5
2. (a) (CH3)3COH (b) BrCH=CHClCH3
(c) (CH3)2CHC(CH3)3 (d) CH3CH2CH(CH3)COOH
(e) CH2OHC(CH3)(OH)CH2OH (f) (CH3)2CHCH(CH3)CH2OH
(g) CH2=CHCCl=CH2 1
mark each 1x7
3. Any
TWO of the followings:
1
mark for structural formula; 1 mark for name 1x16
(a) butan-1-ol;
2-methylpropan-1-ol; butan-2-ol; 2-methylpropan-2-ol
(b) butane;
2-methylpropane
(c) 1-bromopropene; 2-bromopropene;
3-bromopropene
(d) but-1-ene; but-2-ene; 2-methylpropene
4. (a) A: CH3CH(OH)CH2OH H:
CH3CHBrCH3 1,1
(b) Reaction
II: hydrogenation 1
Reaction
IV: addition 1
(c) (i) hydrogen
/ addition 1
(ii) sunlight
/ UV light 1
(d) (i) E:
1-bromopropane F:
2-bromopropane 1,1
(ii) (structural)
isomers 1
(e) (i) colour
turns from purple to colourless / it decolourizes 1
(ii) Test
for unsaturated hydrocarbons / C=C 1
5. (a) (i) Carbon
dioxide and water / steam 1,1
(ii) water 1
(b) absorb
CO2 1
(c) (i) CxHy
+ (x+y/4)O2 ¾® xCO2 + y/2H2O 1
OR 4CxHy
+ (4x+y)O2 ¾® 4xCO2 + 2yH2O
(ii) volume
of excess O2 = 20cm3
volume
of used O2 = 150 –20 = 130cm3 1
volume
of CO2 = 100 – 20 = 80cm3 1
CxHy
+ (x+y/4)O2 ¾® xCO2 + y/2H2O
Vol. 20 130 80
Mole 1 6.5 4
Therefore,
x = 4, 1
6.5 =
y/4 + 4 and y = 10 1
Formula
= C4H10
Full Mark = 48