Biology; Chemistry; Physics: Post your doubts here!

[Lilly2318]

the ans is C. plz explain

 

[FLRNAB]

Hmm,hopefully it'll be accepted.........but in my opinion the paper was easy and i'm afraid the percentile will be high...

For those who get it right it is easy so they think percentile is high lol.

 

[asadalam]

For those who get it right it is easy so they think percentile is high lol.

Yeah thats true though...

 

[M.Omar]

Did any one of u draw dotted lines on graphs just to show the value acquired to the examiner or did u just read the value frm the graph directly and wrote it down as an answer

 

[Lilly2318]

the ans is C. plz explainView attachment 42367

 

[FLRNAB]

Did any one of u draw dotted lines on graphs just to show the value acquired to the examiner or did they just read the value frm the graph directly and wrote it down as an answer

Yeah I made dotted lines.

 

[Lilly2318]

HELP IN Q 16. IF ANYONE HAS NOTES ON EFFECTS OF THESE ON REASCTIONS. PLZ PROVIDE ME

KINDLY HELP IN Q 8 AND 9. the ANS ARE C ND A. plz explain

 

[FLRNAB]

the ans is C. plz explainView attachment 42367

CuSO4 + Zn --> ZnSO4 + Cu

Oxidation is increase in oxidation state, Loss of Electrons
1) Zn ions have Oxidation state +2 which is greater than zero of Zn Atoms. SO4 has -2
2) Zn ions have ox state +2 as protons (+ve charge) are greater in number than electrons (-vs charge) so that means in comparison to Zn atoms they have lost 2 electrons.

Remeber it like this:
Oil Rig - Oxidation is loss, Reduction is Gain of Electrons

or
GOLEH - Gain Oxidation Loss Electron Hydrogen - Oxidation
LOGEN - Loss Oxidation Gain Electron Hydrogen - Reduction.

 

[M.Omar]

the ans is C. plz explainView attachment 42367

it,s like this Cu is deposited as Zinc being more reactive displaces .Cu2+ becomes Cu,so A is incorrect coz it is actually reduction
Reaction does occur B is wrong.D zinc sulphate is soluble and C coz Zinc changes zn2+ such tht it,s is oxidized as increase in oxid state 0 to 2+

 

[asadalam]

Did any one of u draw dotted lines on graphs just to show the value acquired to the examiner or did u just read the value frm the graph directly and wrote it down as an answer

I didnt though i made indication of values on axes by a small line.But it doesnt matter cuz the er and ms say examiner to check the candidates graph and in any case our values were correct so it wouldnt make much of a differnce

 

[M.Omar]

I didnt though i made indication of values on axes by a small line.But it doesnt matter cuz the er and ms say examiner to check the candidates graph and in any case our values were correct so it wouldnt make much of a differnce

In any case it,s just a mark reserved only for correct answer;so I don't think there wud be any problem in not drawind dotted lines or any indication of tht or does it?
plus the grid is small and squares big so it allows easy reading .wht do u think

 

[M.Omar]

I didnt though i made indication of values on axes by a small line.But it doesnt matter cuz the er and ms say examiner to check the candidates graph and in any case our values were correct so it wouldnt make much of a differnce

Second last question is also noticeably similar to w07 chm ppr : D

 

[asadalam]

Second last question is also noticeably similar to w07 chm ppr : D

Yeah,CIE were like what to do and one of them said why not just give them the same questions and everyone must've been like 'Fecking brilliant mate!'.Really laziness on their part.

 

[Dark Destination]

I wrote 29.8 and 24.9 instead of 9.8 and 4.9
Technically they must be right because 29.8 is the maximum rise of the temperature.

I also halved the volumes because the invigilator said Time's up. Panic

I, too, halved the volumes.
If i only had one more minute to read that part, i could have understood that volumes must be the same.
But the invigilator came and started snatching the paper away. .-.

 

[M.Omar]

Yeah,CIE were like what to do and one of them said why not just give them the same questions and everyone must've been like 'Fecking brilliant mate!'.Really laziness on their part.

I think they wud compensate in P1 and P2 though

 

[asadalam]

I, too, halved the volumes.
If i only had one more minute to read that part, i could have understood that volumes must be the same.
But the invigilator came and started snatching the paper away. .-.

My paper was finished with almost 15 min remaining!Where did you spend most of your time?

 

[Lilly2318]

I, too, halved the volumes.
If i only had one more minute to read that part, i could have understood that volumes must be the same.
But the invigilator came and started snatching the paper away. .-.

my ppr didn't well went too. lets all pray forthe percentile to be low and get A

 

[asadalam]

I think they wud compensate in P1 and P2 though

Yeah ATP is always easy,P2 average and P1 really difficult

 

[FLRNAB]

HELP IN Q
16. IF ANYONE HAS NOTES ON EFFECTS OF THESE ON REASCTIONS. PLZ PROVIDE ME

Notes

 

[Lilly2318]

I think they wud compensate in P1 and P2 though

i dont knw why but im unable to score much in these two prs. any tips?