Chemistry paper 42 may/june 11

[Xenon]

if I am wrong its the booklets fault....

By the way, anyone knows how to calculate grade using thresholds and weightings or how the CIE does it

 

[bionology]

ahhh.... summary: exam was not as good as I wanted it to be...
lets just hope everyone achieves their aim/goal

By the way, anyone knows how to calculate grade using thresholds and weightings or how the CIE does it

leave it to CIE themselves ! we can never 'exactly' know how they mark our papers

 

[kahynickel]

This P4 was not unexpected.

As for organic last time Polymerization came was in June 08 and now Jun 11.

Threshold will be 64.

 

[Xenon]

guys how do you compare this year's 42 with the May 2010 P42? The GT that year was 54

 

[diwash]

I think the threshold will be slightly higher than 54...as the paper was easier than m/j 10

 

[MukeshG93]

Is everyone serious about that product at the electrodes question, because I got completely different answers. I don't think it said electrolysis of those compounds in aqueous medium, and even if it did, I think they were present in much larger concentrations (there were no mentions of the standard condition of 1mol/dm3 which is required for the E* values to be compared with that of water. Hence, I think the products would be Ag(s), F2(g), Mg(s), S2O8- (or whatever the booklet says about that) and so on... And in the DNA question, you were supposed to use restriction enzymes after extracting the DNA and the chain polymerase is at the end to attach the radioactive probes to the separated strands (Biology FTW) and I wrote carbon-14 for the radioactive isotope, hope that won't cause me to lose marks. The relationship between the repeat units is that they were structural isomers (which I didn't write). I wrote CuCl2 for that ligand exchange question (big blunder), and I forgot that phenol doesn't react with carboxylic acids to give an ester (or does it?). Anyhow, I am expecting something on the 80 - 90 range, and would that be an A*?

 

[angelgurl]

hey guys i gave chem 4 last june and this june as well
i can say tht last year's paper was way easier than the one this june!!!
I've been through this and last year I had a much better paper.............it's not the difficulty tht matters eventually because in the end even if the paper is easy a lot of ppl lose marks due to careless mistakes

 

[bionology]

Is everyone serious about that product at the electrodes question, because I got completely different answers. I don't think it said electrolysis of those compounds in aqueous medium, and even if it did, I think they were present in much larger concentrations (there were no mentions of the standard condition of 1mol/dm3 which is required for the E* values to be compared with that of water. Hence, I think the products would be Ag(s), F2(g), Mg(s), S2O8- (or whatever the booklet says about that) and so on... And in the DNA question, you were supposed to use restriction enzymes after extracting the DNA and the chain polymerase is at the end to attach the radioactive probes to the separated strands (Biology FTW) and I wrote carbon-14 for the radioactive isotope, hope that won't cause me to lose marks

NO!. it was asked that what are the products at anode and cathode if electrolysis was carried out of these aqueous solution
and PCR is used to "increase" the length of DNA not to make it attached to the radioactive isotope

 

[bionology]

the Gt will range from 60-67

 

[zeebujha]

Can't we add the radioactive isotope to the buffer solution before adding it to the agarose gel (like we do with ethidium bromide stain)?
As far as order of PCR and restriction enzyme is considered, I think either order should be acceptable!

 

[MukeshG93]

Is everyone serious about that product at the electrodes question, because I got completely different answers. I don't think it said electrolysis of those compounds in aqueous medium, and even if it did, I think they were present in much larger concentrations (there were no mentions of the standard condition of 1mol/dm3 which is required for the E* values to be compared with that of water. Hence, I think the products would be Ag(s), F2(g), Mg(s), S2O8- (or whatever the booklet says about that) and so on... And in the DNA question, you were supposed to use restriction enzymes after extracting the DNA and the chain polymerase is at the end to attach the radioactive probes to the separated strands (Biology FTW) and I wrote carbon-14 for the radioactive isotope, hope that won't cause me to lose marks

NO!. it was asked that what are the products at anode and cathode if electrolysis was carried out of these aqueous solution
and PCR is used to "increase" the length of DNA not to make it attached to the radioactive isotope

Please keep your attitude to yourself, you could be a little warm when addressing my question, an abrupt "NO!" was quite unnecessary. As far as the products at the electrodes go, I believe the question did not specify anything about the concentration of the electrolyte. We can only use E* values for comparison when the concentration of the electrolyte is strictly 1.0 mol/dm3, which was clearly not mentioned in the question. Hence, I believe it was the reduction and oxidation of the ions involved in the electrolyte that you were supposed to address when answering the question. If you still believe you are correct, please put forward a stronger argument. As for the PCR, I am not very sure but I am pretty confident, as a Biology student, that DNA polymerase is used to bind two strands of DNA together to form a new double-helix, and I'm not sure how it is supposed to "increase" the length of DNA, as the enzyme used to attach more nitrogen bases along the length of DNA is DNA ligase.

 

[Newbie]

I seriously don't know how people are so damn sure of their paper .... It is really easy to say you are wrong and demoralize others ... please try to think seriously about your response before posting it

 

[MukeshG93]

I seriously don't know how people are so damn sure of their paper .... It is really easy to say you are wrong and demoralize others ... please try to think seriously about your response before posting it

Is this to me? Alright, if I was so damn sure, why would I post that query in the first place? I am not demoralizing others, I am being realistic, and if I just go with what others say, I will be demoralizing myself. I thought of this response seriously because this is what I thought during the exam, how much more serious do you think I can get? Please, this is how things are, this is reality and everyone has to get to say what they have to say and nobody can go against that unless it specifically offends them. I am sorry if I offended you in any way or made you feel demoralized but please, this is reality. I felt offended and demoralized and that is why I am posting here. If you do not want me to post here any longer, I shall respect that. Good day!

 

[Hateexams93]

People i know my post is irrelevant to his topic but i just wanted to ask people who took Chemistry and physics in A level , which subject is easier ?

 

[Newbie]

I seriously don't know how people are so damn sure of their paper .... It is really easy to say you are wrong and demoralize others ... please try to think seriously about your response before posting it

Is this to me? Alright, if I was so damn sure, why would I post that query in the first place? I am not demoralizing others, I am being realistic, and if I just go with what others say, I will be demoralizing myself. I thought of this response seriously because this is what I thought during the exam, how much more serious do you think I can get? Please, this is how things are, this is reality and everyone has to get to say what they have to say and nobody can go against that unless it specifically offends them. I am sorry if I offended you in any way or made you feel demoralized but please, this is reality. I felt offended and demoralized and that is why I am posting here. If you do not want me to post here any longer, I shall respect that. Good day!

No no , It was not directed to you dude... What i was trying to imply was that every person has right to explain and consider their answers correct . No body should boss around and tell people that you are wrong and I am right ....

I was in favor of your post MukeshG93 but I think you misunderstood it ... Ah never mind ...cheers :Yahoo!: :Yahoo!: :Yahoo!: :beer: :beer: :beer: :beer: :beer: :beer: :beer: :beer:

 

[MukeshG93]

I seriously don't know how people are so damn sure of their paper .... It is really easy to say you are wrong and demoralize others ... please try to think seriously about your response before posting it

Is this to me? Alright, if I was so damn sure, why would I post that query in the first place? I am not demoralizing others, I am being realistic, and if I just go with what others say, I will be demoralizing myself. I thought of this response seriously because this is what I thought during the exam, how much more serious do you think I can get? Please, this is how things are, this is reality and everyone has to get to say what they have to say and nobody can go against that unless it specifically offends them. I am sorry if I offended you in any way or made you feel demoralized but please, this is reality. I felt offended and demoralized and that is why I am posting here. If you do not want me to post here any longer, I shall respect that. Good day!

No no , It was not directed to you dude... What i was trying to imply was that every person has right to explain and consider their answers correct . No body should boss around and tell people that you are wrong and I am right ....

I was in favor of your post MukeshG93 but I think you misunderstood it ... Ah never mind ...cheers :Yahoo!: :Yahoo!: :Yahoo!: :beer: :beer: :beer: :beer: :beer: :beer: :beer: :beer:

Sorry, last night I was a bit off due to personal reasons and I guess I let the smallest of things get to me. I am really sorry :sorry: :fool: Thanks for supporting me, and I totally agree with what you had to say. God, I am being such an idiot nowadays. :fool: :fool: :fool: Hope all's good with us dude. I should have thought twice, no at least once, before replying but I don't know what happened to me last night, it was 2AM here in Nepal and my eyes were shutting down the rest of my brain. Gah, I am sorry! :sorry: Friends? :beer:

 

[xarak]

Is everyone serious about that product at the electrodes question, because I got completely different answers. I don't think it said electrolysis of those compounds in aqueous medium, and even if it did, I think they were present in much larger concentrations (there were no mentions of the standard condition of 1mol/dm3 which is required for the E* values to be compared with that of water. Hence, I think the products would be Ag(s), F2(g), Mg(s), S2O8- (or whatever the booklet says about that) and so on... And in the DNA question, you were supposed to use restriction enzymes after extracting the DNA and the chain polymerase is at the end to attach the radioactive probes to the separated strands (Biology FTW) and I wrote carbon-14 for the radioactive isotope, hope that won't cause me to lose marks. The relationship between the repeat units is that they were structural isomers (which I didn't write). I wrote CuCl2 for that ligand exchange question (big blunder), and I forgot that phenol doesn't react with carboxylic acids to give an ester (or does it?). Anyhow, I am expecting something on the 80 - 90 range, and would that be an A*?

*hi-5* i got the same answers as urs(or approx. the same ) nd yes one more thing in the dot nd cross diagram i dint make a key nddd nother blunder.i made a dot for hydrogen nd a cross for nitrogen as well as fluorine how much do i loose?

 

[Newbie]

I seriously don't know how people are so damn sure of their paper .... It is really easy to say you are wrong and demoralize others ... please try to think seriously about your response before posting it

Is this to me? Alright, if I was so damn sure, why would I post that query in the first place? I am not demoralizing others, I am being realistic, and if I just go with what others say, I will be demoralizing myself. I thought of this response seriously because this is what I thought during the exam, how much more serious do you think I can get? Please, this is how things are, this is reality and everyone has to get to say what they have to say and nobody can go against that unless it specifically offends them. I am sorry if I offended you in any way or made you feel demoralized but please, this is reality. I felt offended and demoralized and that is why I am posting here. If you do not want me to post here any longer, I shall respect that. Good day!

No no , It was not directed to you dude... What i was trying to imply was that every person has right to explain and consider their answers correct . No body should boss around and tell people that you are wrong and I am right ....

I was in favor of your post MukeshG93 but I think you misunderstood it ... Ah never mind ...cheers :Yahoo!: :Yahoo!: :Yahoo!: :beer: :beer: :beer: :beer: :beer: :beer: :beer: :beer:

It was never a issue my friend :beer: :beer: :beer: :beer: :beer: :Yahoo!: :Yahoo!: :Yahoo!: :Yahoo!: :Yahoo!: :Yahoo!: :Yahoo!: :Yahoo!: :Yahoo!: :beer: :beer: :beer:

 

[MukeshG93]

Is everyone serious about that product at the electrodes question, because I got completely different answers. I don't think it said electrolysis of those compounds in aqueous medium, and even if it did, I think they were present in much larger concentrations (there were no mentions of the standard condition of 1mol/dm3 which is required for the E* values to be compared with that of water. Hence, I think the products would be Ag(s), F2(g), Mg(s), S2O8- (or whatever the booklet says about that) and so on... And in the DNA question, you were supposed to use restriction enzymes after extracting the DNA and the chain polymerase is at the end to attach the radioactive probes to the separated strands (Biology FTW) and I wrote carbon-14 for the radioactive isotope, hope that won't cause me to lose marks. The relationship between the repeat units is that they were structural isomers (which I didn't write). I wrote CuCl2 for that ligand exchange question (big blunder), and I forgot that phenol doesn't react with carboxylic acids to give an ester (or does it?). Anyhow, I am expecting something on the 80 - 90 range, and would that be an A*?

*hi-5* i got the same answers as urs(or approx. the same ) nd yes one more thing in the dot nd cross diagram i dint make a key nddd nother blunder.i made a dot for hydrogen nd a cross for nitrogen as well as fluorine how much do i loose?

I didn't make a key either and I don't think you'll be penalized for such things, it's just your knowledge of electron placement being tested here.

 

[mrpaudel]

i don't exactly remember but yes, the gaseous 'atoms' Not 'ions' were being in a reaction to make a solid, so that wasn't supposed to be lattice one, so i wrote formation which might be a - or a + value

I am sure that is an acid-base reaction since HF donates a proton and NH3 accepts a proton

CAn we write exothermic reaction there???