Paper 5 Tips !! :)

[Soldier313]

if anyone is done with paper 52 may/june 2012 can u share ur question one apparatus and the step by step description pls ?

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s12_qp_52.pdf

this diagram was by knowitall10
hope it helps!

 

[iKhaled]

June12/52
Do we draw a continuous curve for q2 part c??

its gonna be a straight line passing through the origin..

 

[Haniya Khan]

Can somebody pls tell me how to do serial dilutions question and how to find concentration. Plz plz plz plz plz

 

[iKhaled]

t

this diagram was by knowitall10
hope it helps!

View attachment 25370

thank uuuuuu

 

[Haniya Khan]

Pls pls pls plzzzzzzzzzz plzzz helppp

 

[xxfarhaxx]

cuco3 on the x axis and mass lost on y axis.... sry for llate reply.... :/

ohh since ur axis is diff frm mine, im nt rely sure hw to do it. bt fr my graph ths is hw i gt it...my x axis ws mass of carbonate n y- mass of CuO
so u gt a point in da graph n read its values ... mine were x-4.4 y-3.05
frst find the moles of CuO. (mr=79.5) do divide 3.05/79.5= 0.038
consider ratio of CuO : CuCo3
2 :1
so 0.038---> x
find x. i.e 0.038/2=0.0192 of mols of carbonate. usin ths fnd the mr of the crbonate i.e. mols=mass/mr, calculated value will b 229.4
nw to fnd da mr of the CuCO3.Cu(OH)2.xH2O, mr of ths= 221+18x
221+18x=229.4
x=0.46 whch is appro=0.5

i knw its a mess, bt hope u gt it sumhw..i rely dnt knw hw to do fr ur graph!

 

[Wanderer]

its gonna be a straight line passing through the origin..

Are you sure? Cause ms says it should be an initial straight line but should terminate in a curve?

 

[Haniya Khan]

Can somebody pls explain me serial dilution making and concentration related question. Vl b very thankful. Plzz

 

[Soldier313]

Aoa wr wb,
- Can someone please help me for qn 2, how do we know that the examiner wants the values of part 'bi' to 2 significnt figures, and for part 'bii', to 2 decimal places?
- Secondly, why is the ms stating that the ratio calculated in 'b ii' must be I:Zn and not the inverse, i mean i did it as Zn:I, but the ms clearly states not to do that:/
- And for part 'e' of the same qn, the reasons for the anomalies in the ms don't quite agree with my understanding, can someone please elaborate?

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w09_qp_51.pdf
http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w09_ms_51.pdf

MaxStudentALevel xhizors and @ all other p5 candidates
Thanx a lot ​

 

[iKhaled]

Are you sure? Cause ms says it should be an initial straight line but should terminate in a curve?

oh the examiner reports says " Most candidates drew a straight line rather than a line which curved upwards after a pressure of around 200kPa"

i am one of these "most candidates" lol so it is supposed to be a line which will curve after 200kpa

 

[Xtremite]

do you guys have pics of Q1 planning solved papers? I really really suck at Q1.. Please plzzz upload them.
xhizors knowitall10 Soldier313 iKhaled Gémeaux xxfarhaxx all you guys.
Just take a pic of all or as much as u can, the planning experiment qstns with ur mobile n upload it. wont take much time but will surely help us.

 

[Student12]

how do we draw the construction lines ? or how to find the slope? Its asked in almost all questions ? :O HELP! for example:
http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w10_ms_51.pdf
http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w10_qp_51.pdf
Question 2 part (e) (i)

 

[Gémeaux]

Haniya Khan It'd be better if you could post a question related to it. In general, for serial dilution you take a part from the solution, dilute it, and for next dilution take a part from the diluted solution. For example, if you have initially a sol of conc 1mol/dm^3, take one part this and nine parts distilled water. This would give you a solution of conc 0.1 mol/dm^3. Next take one part of 0.1mol/dm^3 sol and add nine parts water to get a solution of 0.01 mol/dm^3.

 

[Gémeaux]

how do we draw the construction lines ? or how to find the slope? Its asked in almost all questions ? :O HELP! for example:
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w10_ms_51.pdf
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w10_qp_51.pdf
Question 2 part (e) (i)

Construction lines are just the dotted lines you draw from a point on the graph to the axis.

 

[iKhaled]

C
o
Construction lines are just the dotted lines you draw from a point on the graph to the axis.

we can't draw a triangle?

 

[Student12]

C
o
Construction lines are just the dotted lines you draw from a point on the graph to the axis.

Is it like how we find the gradient ? (y2-y1) / (x2-x1)

 

[Gémeaux]

we can't draw a triangle?

Yes, we can. That is up to us, both serve the same purpose, don't they?

 

[Gémeaux]

Is it like how we find the gradient ? (y2-y1) / (x2-x1)

Yup, slope is an other word for gradient.

 

[Boss.Mentalist.Awesome]

i just want to be sure if i am doing the serial dilutions correctly
Lets say i have 2 moldm^-3 of and acid...
and i am making my total volume constant to 100 cm^3
I want a solution of acid with concentration 1 moldm^-3
So in this case will case i will add 50 cm^3 of distilled water and 50cam^3 of acid
now lets say i want to make a concentration of 0.5 moldm^-3
so i will add 25 cm^3 of acid n 75 cm^3 of distilled water
(Please tell me ASAP...if i am correct or not)
JazakAllah!

 

[Iadmireblue]

oh the examiner reports says " Most candidates drew a straight line rather than a line which curved upwards after a pressure of around 200kPa"

i am one of these "most candidates" lol so it is supposed to be a line which will curve after 200kpa

Well according to CIE a line can mean a curve or a straight line,but a straight line means it's only a straight line.
CIE is weird.