Chemistry Paper 61

[joanna omar]

melting not boiling

sure ! and what abt if the answer is chromatography ?

 

[*MK*skydiver :D]

difference is they said they were heating the solution not the crystals

That is exactly the point ........ that they said "further heating " ...and at 400 something degrees,the iron(II) is oxidized
....plus the question said "heating the solution for a few minutes"..i dont think that a few minutes on the bunsen burner would make it reach 480 degrees !!

Plus ,all those who wrote this answer of iron being oxidised into iron(III).......can you answer this question ::::
how are iron (II) sulphate crystals obtained ?
By heating the iron sulphate solution for a few mins until crystallisation ..................

if what theyre saying is right , then we cud've NEVER been able to obtain iron(II) sulphate crystals!!

COME ON PPL !! :/

 

[*MK*skydiver :D]

I wrote tht too...bt one ov my friends has written 'hydrated' ammonium carbonate....i think tht will account fer two marks i guess!! :/

hydrated ? how come ? :/
sublimes is a reasonable answer ....but how about the litmus paper that turned blue ..what does that mean ?

 

[bluefa1con]

That is exactly the point ........ that they said "further heating " ...and at 400 something degrees,the iron(II) is oxidized
....plus the question said "heating the solution for a few minutes"..i dont think that a few minutes on the bunsen burner would make it reach 480 degrees !!

Plus ,all those who wrote this answer of iron being oxidised into iron(III).......can you answer this question ::::
how are iron (II) sulphate crystals obtained ?
By heating the iron sulphate solution for a few mins until crystallisation ..................

if what theyre saying is right , then we cud've NEVER been able to obtain iron(II) sulphate crystals!!

COME ON PPL !! :/

exactly
boiling the solution will concentrate the solution and crystallisation takes place

 

[*MK*skydiver :D]

sure ! and what abt if the answer is chromatography ?

I wrote chromatography ...and so did most of my friends ....

 

[*MK*skydiver :D]

ikr!
i wrote ammonium carbonate
n ithink its rite cuz its just one compound "W" unlike in other pst pprs u hav like 2 or 3 compounds
also i cant remeber but was there any test for other ions??

i dont rmmbr either :/

 

[Nawaf Dandachi]

shut up..

Your mom

 

[Nawaf Dandachi]

nawaf ana mohammed yasser can we say it is redox

who is Mohammed yasser? and No it's not REDOX

 

[Nawaf Dandachi]

thats right, ya have to mentioning the same volume etc etc

Fairness is actually worth half of the problem.

 

[Nawaf Dandachi]

it IS ryt, my teacher said so. cn u stop bein da BOSS plzz? u r actin lyk u knw evrythin n da rest of us knw nothin. evrybody makes mistakes. it's not lyk we r perfect!!!

Who said so? We are discussing, why are you mad?

 

[Nawaf Dandachi]

I wrote rate of reaction decreases coz iodide is less reactive compared to chlorine...
Is tht ryt?!

well and silver is less reactive than lead, I think it is right. Ask your teacher he knows better. but I'm pretty sure it's yellow precipitate

 

[Nawaf Dandachi]

What the heck is double displacement.. NEVER i've seen an answer DOUBLE DISPLACEMENT through all the 8 years past papers i went through... its PRECIPITATION!!

Hellow, There is single and double dispacment, I have solved from 90's so STFU.

 

[Beedo]

1-how much was the amount of heat produced by pentanol? (I wrote it 45)
2-what if I wrote in question 1 no more evolve of gas instead of no more effervescence , will they consider it right?
3-How many marks will I lose if I made the intersection of the 2 st. lines in graph wrong and so got the answer depending on it wrong? (The graph was for 4 marks , the question was for 3 marks)

 

[EpicLol]

It was Easy, the last question answer was :-
1. Place each Corrosion inhibitor in 3 test tube of equal amount.
2. Take 3 steel nails and place them in 3 water bowl.
3. Place each inhibitor in bowl.
5. Leave it undisturbed for 3-4 days in presence of air.
6. After 4 days, Remove the rust which will be Flaky brown solid (FE2OH3.xH2O) and dry them and weigh each of them.
7. The one which has more weigh will be least effective corrosion inhibitor and one with lower weight will most effective corrosion inhibitor.

What if I skipped out step 6 and said just look at it and the one with most rust is the least effective? And what if I said put the nails in a test tube and add corrosion inhibitor to the test tube....how many marks would I get out of 7?
Thx

 

[EpicLol]

http://www.scribd.com/doc/93877385/Upload-Paper-4-1?secret_password=7avle997pz1j07r3vxa .............................for paper 4
http://www.scribd.com/doc/93877294/2012-Maths-Paper-2?secret_password=2njbfwspjhnto8n5bivw.......................for paper 2

This is 2012 May/June?!
How come u have these papers when I am like doing the exam on june 11 and june 13??

 

[raysonzaffar]

This is 2012 May/June?!
How come u have these papers when I am like doing the exam on june 11 and june 13??

wht u hav thm on june 11 & 13...............it was may 11 and may 14.......................which country r u from ??!??!????!!!!!!!!!!!!!???????????

 

[Jisu]

This is 2012 May/June?!
How come u have these papers when I am like doing the exam on june 11 and june 13??

wat??
we finished these exams on da 8th of May and da 14th of May
r u sure u take 0580?
my friend gave em to me n i uploaded them

 

[IGCSE O/L student]

Who said so? We are discussing, why are you mad?

look bro, I kinda misunderstood you, ok?!
I mean I lost my temper because you were sort of acting like you knew everything, and the rest of us knew nothing. That's the way I saw it, but in reality, I think you were trying to help the other candidates.
I'm sorry.

 

[Jisu]

Hellow, There is single and double dispacment, I have solved from 90's so STFU.

whoa dude
better hold it in, man~
wid dat temper of urs, someone shud stop u
we hav da right to do so
who said so, u may ask?
well, i dont think a rule is necessary to tell u to stand up for ur friends...

 

[Jisu]

look bro, I kinda misunderstood you, ok?!
I mean I lost my temper because you were sort of acting like you knew everything, and the rest of us knew nothing. That's the way I saw it, but in reality, I think you were trying to help the other candidates.
I'm sorry.

u got no need to apologize sista
u were standin up for urself n ya friends
dat guy ought to learn sth fom ya, aint it?