Close

2008
Wed
12
Nov

# GCE O-Level 2008 Oct/Nov Physics & Chemistry Paper 1 Suggested Answers & Solutions

(46)
Tuition given in the topic of Little Miss Loi the Science Tutor (archived) from the desk of at 5:31 pm (Singapore time)

UPDATE: My list of suggested answers for the Combined Science (Physics, Chemistry) 5116 Paper 1 is now up (see below) 😀

Those of you taking other combinations (i.e. 5117 or 5118) in this ‘O’ Level would’ve probably gone through the same set of 20 Physics or 20 Chemistry MCQs on Tuesday.

Hi it’s me again!

Now that (most of) you have been liberated, I’ve drafted a list of my suggested answers for todays Chemistry Paper 1 and Monday’s Physics Paper 1, along with the relevant workings and explanations for each answer (where applicable).

2008 O-Level October/November Science Paper 1 Suggested Solutions

2008 O-Level October/November Combined Science (Physics, Chemistry) 5116 Paper 1 Suggested Solutions – click to download

So did your tikam-tikam MCQ answers tally with mine? Do leave a comment if you spot any mistake but please be gentle with me ok, even though I can be quite ductile and malleable 😛 Haha.

### Revision Exercise

To show that you have understood what Miss Loi just taught you from the centre, you must:

1. Passer-by commented in tuition class

2008
Nov
12
Wed
6:16pm

1

Hello,

how much do you think the A1 scores for Phy and Chem will be this year?

Based on your marking schemes, I got only 36 for Phy and 39 for Chem.

For question 11, I think that you should add a note that liquid and solid's volume should be negligible as they take up much less space compared to a gas. Thanks =)

2. Another passer-by commented in tuition class

2008
Nov
12
Wed
6:26pm

2

Physics Qn15: Temperature increases, force exerted per particle increases, so shouldn't the frequency decrease such that the TOTAL force acting on the piston remains the same? (because the area of piston remains the same and you have to maintain a constant pressure).

In other words, could you rethink Option B?

3. c commented in tuition class

2008
Nov
12
Wed
7:46pm

3

Hey there (:

Able to do the answer scheme for the MCQ papers 5118/5116?

Thanks
XOXO

4. Clare commented in tuition class

2008
Nov
12
Wed
9:22pm

4

Ms Loi, you're super lame as always! If I really do somehow by some miracle, get an A for Physics, I'll treat you to like twenty bowls of corn soup. HAHA. 🙂

5. Little Miss Loi commented in tuition class

2008
Nov
12
Wed
9:54pm

5

Hello Passer-by 🙂

As all reactants in qn 11 are in gaseous state, this should be a clear sign that the volume change concerns only the volume of the gases.

But you're right too that the volumes of liquids & solids are negligible to the volumes of gases e.g. 1 mole of steam = 24000 cm³ vs 1 mole of water = 18 cm³

6. Anoneemers commented in tuition class

2008
Nov
12
Wed
10:28pm

6

I got 38 for both physics and chemistry

Physics question 15 i wrote A for 2 reasons
1) For rate of collision, I saw 2 "greater" so i chose greater =.=
2) I thought the heated gas collide more with piston to move it out...

Anyway is 38 a safe mark to get A1?

7. Little Miss Loi commented in tuition class

2008
Nov
12
Wed
10:31pm

7

Hi Anoneemers and Another passer-by! This sounds like a traffic junction 😛

As Another passer-by mentioned, the pressure is due to the force exerted by the particles on the piston, which is in turn determined by rate of collision (i.e. force acting on a unit area per unit time).

But in order for the pressure to remain unchanged, the rate of collision must be the same.

FYI, this unchanged rate of collision (despite the faster molecules) is actually due to the greater average inter-molecular distance/distance to the piston caused by the increase in volume.

So you can think of this as effectively 'cancelling' out the ↑ rate of collision due to ↑ speed of molecules, resulting in no change to the rate of collision.

8. Little Miss Loi commented in tuition class

2008
Nov
12
Wed
10:34pm

8

c: Look again!!!

Clare: TWENTY BOWLS ONLY????!!!!!!!!!! My elder sister says she also want!!!

9. Clare commented in tuition class

2008
Nov
12
Wed
10:40pm

9

ONLY?!?!!?!?!?!!? WHAT. I THINK YOU'LL BE QUITE FAT BY THEN! HAHAHA!

10. shelyce commented in tuition class

2008
Nov
12
Wed
10:48pm

10

For the Chem mcq question no. 3, it ask which gases change the colour of damp red litmus paper. But chlorine change the colour of damp blue litmus paper. So the answer cannot be A.

11. Traffic Light commented in tuition class

2008
Nov
12
Wed
11:14pm

11

Any idea how the moderation would be like? Like how many marks to get A1? Cause I'm in a super risky position, got 75% but likely no 85%.. feeling very not at ease now. Since you all are teachers, can share the % required for A1 in previous years if moe got release?

12. Traffic Light commented in tuition class

2008
Nov
12
Wed
11:18pm

12

For pure physics question 9, can explain why it is A? Cause I learnt that lower CG means more stable because the chances of line of action of weight lying within the base is higher, so why must raise over the rope? I put D btw, cause all the other answers look wrong to me.

13. Gabbs commented in tuition class

2008
Nov
12
Wed
11:30pm

13

Hi, 5116/01 paper , Qn 17, I also write B which is the largest resistance one(your ans too^^). But dunno why my tcher gave his ans as C(lowest resistance).

14. angelyn commented in tuition class

2008
Nov
12
Wed
11:31pm

14

hi,
why is qn 38 of phy/chem 5116 B?
isn't alkanes saturated? so shdn't it be A?

15. Traffic police commented in tuition class

2008
Nov
13
Thu
12:43pm

15

Physics Q37...Can I say that the point Y is outside the magnet and thus Y is weaker than X and Z?

16. Little Miss Loi commented in tuition class

2008
Nov
13
Thu
7:04pm

16

Good day everyone!

shelyce: Since hydrogen chloride is acidic, and carbon dioxide and sulphur dioxide are acidic oxides that dissolve in water to form acids, options B, C and D are eliminated because acids turn blue litmus red.

As for chlorine, as I have mentioned in my suggested solution, it actually bleaches the litmus paper since it's a bleaching agent, but not before it turns the blue litmus red briefly (due to the formation of HCI).

Traffic Light(???): Actually I can't say that Option D is wrong per se but it doesn't really explain why a pole is carried.

In our case, the rope is the pivot and the man (consider him as a point mass with a narrow base) will easily lose his balance when his CG does not lie in line with the rope.

When this happens, he can shift the (long, long) pole accordingly to create a restoring (large) moment on his body to bring his CG back in line with the rope, thereby making it easier for him to keep his balance (i.e. CG) over the rope so that he doesn't faaaaaaaaaaaaaaalllll .....

Gabb: Hey now that you mentioned, I took a look at the question again and found that it asked "In which circuit will the CELL lose its energy the fastest?"

I'm now inclined to believe that the answer is C due to the fact that the parallel circuit draws more current from the cell and thereby making it lose energy faster.

I'll have a check first with other people before confirming the change to my answer.

angelyn: In a hydrogenation process, saturated margarine is converted from unsaturated liquid vegetable oil via an addition reaction (which is the characterized reaction of the alkene family because it is unsaturated (i.e. contains C=C bond)

Alkane family, on the other hand, undergoes substitution reaction because it is saturated (i.e. contains C-C bond)

Traffic Police Sir! But point Y lies inside the solenoid (check your diagram again)!

... and I kept to the speed limit on my way back just now!

17. Little Miss Loi commented in tuition class

2008
Nov
13
Thu
7:06pm

17

And Clare! I think I can still afford to! Tsk tsk.

18. Traffic Light commented in tuition class

2008
Nov
14
Fri
1:49am

18

Can see where you are coming from, but his CG will definitely be above the rope even if he does not hold the pole isit? Cause he is not some ring shaped object and no part of his body is below the rope, at least before he falls.

19. kelvin commented in tuition class

2008
Nov
14
Fri
10:09am

19

hey will you be posting the pure biology results?

20. chanhankiang commented in tuition class

2008
Nov
14
Fri
1:47pm

20

hi. i search the whole search engine and realise you are the only person who put the answers up till this moment. cheers. will u put up the biology paper 1 answers? i am interested to check out your explanation provided rather than the answers because it really o help. thanks

21. Miss Loi Friend Miss Loi on Facebook @MissLoi commented in tuition class

2008
Nov
14
Fri
6:07pm
22. Little Miss Loi commented in tuition class

2008
Nov
14
Fri
8:04pm
23. Traffic police commented in tuition class

2008
Nov
14
Fri
10:50pm

23

I think Physics question 9 is not D because there is no such thing as spreading out his weight... As in every part of his body has a weight and his weight cannot be transferred to the rod. Isn't that right?
Combined physics question 17 is C because P=VI, V is fixed for a cell so higher I means greater energy loss right?

24. Little Miss Loi commented in tuition class

2008
Nov
15
Sat
2:01am

24

OK Gabbs & Traffic Police Sir, I've amended the answer to Qn 17 in the Combined Science 5116 Paper 1 to C (the // circuit), since the lowest resistance will draw the greatest current from the cell, thereby causing the cell to lose its energy the fastest.

I think countless students have fallen through the trapdoor for this one. Sigh.

Traffic Light: Perhaps some stickman diagram would help in the understanding of Pure Physics Qn 9:

In 1) the man is balanced on the rope, with his CG directly over the rope as you've mentioned.

But with such a narrow base, unless he is 黃飛鴻, a slight wind or a slight muscle cramp that causes a slight shift of his CG either side of the line of pivot will create a moment about the pivot that will cause him to fall (see 2) ) very quickly, even though his CG is still above the rope for a brief moment when he begins to fall.

With a long pole that commonly comes with weighted ends, he can save himself from falling by shifting his pole to create a huge restoring moment (the weighted end of the pole x the long perpendicular distance) on the opposite end (see 3) ). He can also achieve this somewhat by stretching out his short puny arm but its effect will be limited.

In reality, the pole also helps in increasing the man's moment of inertia, making him more 'resistant' to falling via distributing his weight away from his ankles to both ends of the pole (which is basically what Option D says, but as explained above this isn't the only thing it does - the ultimate aim is still to maintain his CG directly over the rope).

25. Amanda commented in tuition class

2008
Nov
15
Sat
2:13am

25

Don't have answers for 5154/01? Discrimination of old syllabus! heh 😛

26. Traffic Light commented in tuition class

2008
Nov
15
Sat
12:01pm

26

I understand already =D Thank you! 谢谢! The drawing must have took you some time.

27. BTA commented in tuition class

2008
Nov
15
Sat
8:56pm

27

Thanks a lot for the answers! They were a great help!
I scored 17/20 for Physics and 17/20 for Chemistry. I think I'm a little risky!

28. Little Miss Loi commented in tuition class

2008
Nov
16
Sun
1:43pm

28

Amanda: Do you still have the 5154 question paper? By the way, you know my sister? She's standing behind me exclaiming "Amanda! Dun come in and 捣蛋 lah!"

Traffic Light: Those diagrams? I asked someone to draw for me *giggles*

BTA: 17/20+17/20 = 34/40 (85%) = risky?! Something happened in your Paper 2/3?

29. Amanda commented in tuition class

2008
Nov
16
Sun
2:49pm

29

*giggles* hello Miss Loi! 😛

I still have it... Mine's Chem/bio. How to send to you? lol

30. Kenneth commented in tuition class

2008
Nov
16
Sun
5:40pm

30

Hi, sorry to post it here, but could i get the answers for A Maths 4037/1 ? Thanks loads

31. BTA commented in tuition class

2008
Nov
16
Sun
11:02pm

31

Hey I thought it would be safer to get at least 85% to secure an A1 and my MCQ is only borderline so I thought I was a little risky. Nothing much happened in my Paper 2/3 but if something did happen that I did not come to realise sooner, my MCQ will not be able to pull it up. Furthermore, I was expecting full marks or at least 90% for MCQ so I thought I was risky!

32. chanhankiang commented in tuition class

2008
Nov
18
Tue
10:43am

32

yes you are risky. this year is a strong batch. wads ur sch

33. BTA commented in tuition class

2008
Nov
20
Thu
2:37am

33

Hey Chanhankiang, I'm in Crescent Girls' School. 😀

34. Miss Loi Friend Miss Loi on Facebook @MissLoi commented in tuition class

2008
Nov
20
Thu
9:46pm

34

Sorry to interrupt your little banter ...

Amanda + Kenneth, did you receive Miss Loi's email? Do send your question papers asap to Jφss Sticks' Marking Services ok?

35. Kenneth commented in tuition class

2008
Nov
22
Sat
11:37am

35

oh yeah hi. I did recieve it.
But it was a misunderstanding.
I just realised that wasn't my paper.
I'm sorry.

36. Little Miss Loi commented in tuition class

2008
Dec
4
Thu
2:46pm

36

Amanda: Thanks for your question paper! After being nagged to the brink of death by my sis, I've finally managed to put up my set of 5154/01 solutions 😛

The chemistry questions are exactly the same as those in 5116/01! Lazy buggers ...

37. TheNoob commented in tuition class

2009
Jan
2
Fri
9:04am

37

I scored 36/40 for bio paper 1, and 31/40 for chem paper? Do you think i can still secure A1 for both papers? Im quite confident for paper 2 ><

38. Little Miss Loi commented in tuition class

2009
Jan
3
Sat
12:25am
39. complicated commented in tuition class

2009
Nov
10
Tue
9:55pm

39

do you have the answers for physics paper 2009 5058/01?

40. Little Miss Loi commented in tuition class

2009
Nov
11
Wed
12:48pm

40

Hi complicated, without further ado I've managed to work out the not-so-complicated answers to the 2009 Physics P1 MCQ 😉

41. complicated commented in tuition class

2009
Nov
11
Wed
4:31pm

41

haha thanks, i got 39...last min i change the correct ans to wrong...

42. complicated commented in tuition class

2009
Nov
13
Fri
12:26pm

42

hi, sorry to bother you again...can you also put up the answers for 2009 biology(5094/01) and chemistry(5072/01) thanks so much

43. carpaccio commented in tuition class

2009
Nov
14
Sat
11:07pm

43

whoops sorry it is the chemistry answers for
pure chemistry paper 1 5072/01. my mistake for posting in this section.

44. dhyna commented in tuition class

2010
Oct
1
Fri
12:01am

44

thanks miss loi......these answers will help me a lot in preparing for my o level.

45. sarah rizwan commented in tuition class

2011
Apr
1
Fri
8:15pm

### One Reaction

1. Pinged by Chemistry Hub

2009
May
22
Fri
12:48pm

46

Chemistry Hub...

[...] Amanda: Thanks for your question paper! After being nagged to the brink of death by my sis, I've finally managed to put up my set of 5154/01 solutions :P. The chemistry questions are exactly the same as those in 5116/01! Lazy buggers ... [......

• ### Latest News

With the current COVID-19 situation, all joss sticks sessions have been ZOOM-ed away from Novena and are currently held online.

Please check our secondary / O level maths group tuition schedule for updates throughout this circuit-breaker period.

The 2018 exam papers are here! Miss Loi's 2018 Maths Exam Papers are finally here!

* Please refer to the relevant Ten-Year Series for the questions of these suggested solutions.