OLEVEL COMBINE SCIENCE PRACTICAL

• Nokia-lover

  16 Oct 08, 18:40

  Anyone have the answer to this year 2008 combine science  practical? 

  My friend asked me to post this such that he could compare the answers. 

  2008 paper seems super hard, if i m not wrong there is a ruler experiment then plot graph & stuff. 

  So if anyone are free to post their answers here. Good luck for those taking O level 

  this year.:]

• Lee012lee

  16 Oct 08, 18:59

  Finish exam means finish already lah. Check for wat. Check already also cannot change the answer lah.

• popikachu

  16 Oct 08, 20:54

  ^^

  i did, physic i kinda easy but chem...

  Chem like no see this type of question before leh...

  The unknown substance is dunno what... contain so many things?

  They said it contains K, Br and O only, but our test shows more substance in it -.-"

  Burning the salt on a wooden splint - Purple flame.

  First test, glowing splint relight, Oxygen is present.
  
  Second test, add HNO3 then KI and then Starch.
  HNO3 acidify the substance and then plus KI and give a yellowish solution, Lead Is present in this test...
  Then add starch, become purple... I dunno this is for what...

  Thrid test, add AgNO3, white ppt is form, Chlorine is present...
  Then add ammonia, white ppt is again form, insouble in excess, which means it contain either lead(II)or Aluminium.

  Fourth test, add AgNO3, again white ppt is form, Chlorine is present...
  Then add ammonia, white ppt, soluble in excess. You will see that become colourless after your add the 1cm^3 of ammonia... 1cm^3 of ammonia is enough to see it become colourless... This shows Zinc is present...

  HOWEVER,
  this is just what i wrote in my paper and there are A LOT OF ERRORS HERE!

  so dun be sad if different as yours...

   

• popikachu

  16 Oct 08, 20:58

  PHYSIC!

  Gravity of Earth is 10, so your answer should be 9 - 11...

  Last 2 question, they ask for why got error and how to change it...

  Fuck... should have pay attention in class more T.T

• popikachu

  16 Oct 08, 22:05

  Quoted from other website:
  
  (a) Purple flame -1
  
  (b) Salt dissolve to form a white liquid -1
  White liquid forms into solid after heating -1
  White fume given out -1
  Gas produced relights glowing splint -1
  
  (ci) When added HNO3, solution turns pale yellow -1
  When added KI, colour of solution darkens to orange/brown -1
  When added starch, solution turned black
  
  (cii) White ppt observed when AgNO3 was added, -1
  More ppt observed when 1cm3 of NH3 is added. -1
  
  (d) White ppt observed when AgNO3 was added dissolved solid T -1/2m
  Ppt dissolve in 2cm3 of NH3 -1/2m
  
  (e) Gas evolved in (b) is Oxygen -1
  Displacement reaction occurs in (c), which is a redox reaction -1
  I- is being oxidised to I2, while Br2 is being reduced to Br- -1
  Solid T is soluble in Aqueous ammonia -1

• gunner77

  16 Oct 08, 22:25

  chem screwed up

  physic ok. my g force = 9.6

  % of error = 7.08%

• Maith

  16 Oct 08, 23:34

  die liao...sigh nvm,at least tmr is holiday for us :D

• xXBlack_RebelXx

  16 Oct 08, 23:53

  wow man... it does seem very hard. Eh did you guys practice by using the qualitative/volumetric analysis 5 year series?

• gunner77

  16 Oct 08, 23:57

  the chem was totally unexpected

• xXBlack_RebelXx

  17 Oct 08, 00:00

  Originally posted by gunner77:

  the chem was totally unexpected

  
  is there a way to prepare for chem practical?

   

• gunner77

  17 Oct 08, 00:02

  Originally posted by xXBlack_RebelXx:

  
  is there a way to prepare for chem practical?

   

  
  buy the ten year series practical and do at sch ?

• xXBlack_RebelXx

  17 Oct 08, 00:16

  what? there's a practical paper tys??? are you serious?

   

• gunner77

  17 Oct 08, 00:26

  ya. damn sure.

• xXBlack_RebelXx

  17 Oct 08, 00:31

  haiyaz... but actually not much of a use unless you really DO the practicals. Because I don't think that there will be any answers to refer to. Its pretty pointless, you can only anticipate what sorts of questions that will come out. Perhaps just try to do the theoretical aspects of it.

• gunner77

  17 Oct 08, 00:33

  i tink my chem practical gonna get 2/15

  i compare my ans with the above, gone case.

• youyayu

  17 Oct 08, 00:35

  Originally posted by gunner77:

  i tink my chem practical gonna get 2/15

  i compare my ans with the above, gone case.

  poor gun

• gunner77

  17 Oct 08, 00:38

  Originally posted by youyayu:

  poor gun

  
  seriously i screwed up the whole chemistry component.

• Maith

  17 Oct 08, 00:54

  Originally posted by gunner77:

  
  seriously i screwed up the whole chemistry component.

  u're not alone..

• gunner77

  17 Oct 08, 00:56

  Originally posted by Maith:

  u're not alone..

  
  u take the same syllabus as me?

• popikachu

  17 Oct 08, 01:31

  Dun worry... there is this thing call the dunno what curve...

  Everybody is doing equally badly...

  ^^

• Vendettus

  17 Oct 08, 10:21

  Originally posted by popikachu:

  Dun worry... there is this thing call the dunno what curve...

  Everybody is doing equally badly...

  ^^

  Yup.

  If everyone didn't do it too well, then they'll shift the passing mark down.

• Maith

  17 Oct 08, 16:44

  Originally posted by gunner77:

  
  u take the same syllabus as me?

  yup 

• gunner77

  17 Oct 08, 16:45

  Originally posted by Maith:

  yup 

  
  5152?

• popikachu

  17 Oct 08, 17:53

  5152 is the old slyybus right?

  i know i take different one from my sec 4 friends... lol

• Nokia-lover

  17 Oct 08, 19:27

  tyty,anyway my friend said there such be moderation, so worried not