Hi Students (and parents),
Thank you for all your email enquries on our annual Organic Chemistry Mastery Workshops 2009 for O Level students.
As mentioned that in 2008 GCE O Levels Chemistry Exams, Organic Chemistry plays a large part of the questions that came out in Paper 1 (Multiple Choice Questions) and 2 (Written).
Today i am going to share with you some of the multiple choice questions that came out. I will help you by directing you to the “sub-topics” of Organic Chemistry that the question is based on:
Question 1: Under sub-topic ” Fuels”
In how many of the following can paraffin (kerosene) be used as the energy source?
Aircraft, Air Conditioning Units, Cars, Domestic Cooking, Heavy Lorries, Power Stations
A) 1
B) 2
C) 3
D) 4
&
Question 2: under sub-topic “Alkanes”
Which statements are true of alkanes?
1. Their general formulae is CnH2n
2. They are flammable
3. They react with chlorineA) 1 and 2 only
B) 2 and 3 only
C) 1 and 3 only
D) 1, 2 and 3
&
Question 3: under sub-topic “Alkenes”
Two gases, X and Y, have the following properties.
1. X dissolves in aqueous sodium hydroxide but Y is insoluble
2. Y burns in excess oxygen to give X and water only
3. Y does not decolourise aqueous bromineWhat are gases X and Y respectively?
A) Carbon monoxide and ethene
B) Carbon monoxide and ethane
C) Carbon dioxide and ethene
D) Carbon dioxide and ethane
PS: Do attempt the questions and leave your answers & suggested reasoning in the “Leave A Reply” section below
PPS: If you would like more Tips, Notes and Questions on Organic Chemistry, please check out the archives (older blogposts) by CLICKING HERE
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- O Level Chemistry: Organic Chemistry – Addition Reaction
- O Level Chemistry – Mini Series on Tough MCQs Part 3
- More Error in Marshall Cavendish GCE O-Level Chemistry Matters Textbook – Part 2
q1 a
q2 b
q3 d
continew with tha sprit
Hi Mr Chua!
Ans 1: A
I don’t get it, why is the answer B? I thought natural gases are used in cooking, not kerosene ?? *confused.
Ans 2: B
Ans 3: D
Thanks!!
my answer are ,B,B and D because th third question bromine decolorised only in
saturated hydro carbons A and C are not saturated they are unsaturated and the
answer will be from B and D my answer is D because in combustin
Hi Garcia,
Where are you from?
In domestic cooking and power stations, we do not generally use kerosene if other suitable choices of fuel are present.
Hope this information helps. =)
To Your Academic Success in Chemistry,
Sean Chua
Hi James,
General Molecular Formula for Alkanes Homologous Series is CnH2n+2.
Hope this information helps. =)
To Your Academic Success in Chemistry,
Sean Chua
i think the answer is c which is 3 cause only air condition units,domestic cooking and power stations use kerosene
Huh??? Formula for alkanes is C2H2n+2. Lols.
Glad you learning from your mistakes!
Review and revise towards excellence!
cheers
Sean
Well Done Jun Wei and Winston!
Glad you are taking actions!
To Your Academic Success in Chemistry,
Sean
Yah, sorry about the error
All Answers are correct, but one of the explanations are wrong. Alkanes have a general formula of CnH2n+2, not +1
Q1) Answer is B
cos usage of paraffin is for only cooking and aircrafts
Heavy Lorry should probably use diesel and cars use petrol.
Q2) Answer is B
Option 1 is of course wrong cos formula for alkane is CnH2n+1
Option 3 is correct cos alkane undergo substitution rxn.
Option 2 must be correct cos by elimnation
Q3) Answer is D
Y does not decolorise aq bromine, means that it is a saturated hydrocarbon and not alkene.
So definitely, options B/D is the answer. I believe that carbon dioxide is produced in excess oxygen and combustion occurs.
Therefore, its D.
Carbon dioxide