Chemistry paper 42 may/june 11

[bionology]

darn it ! I just wrote blue
yeah i checked, it's dark blue

 

[bionology]

yeah ph was 2.28 or 3... below the ph part, we had to draw dot and cross structures of NH3, NH4+F- and HF... and we had to tell the 3 types of bonding in NH4+F- ... i wrote ionic bonding b/w oppositely charged ions, covalent bonding b/w N and H ... and dative bonding b/w N and F ... i hope that's right?

na na, we had to tell what was the 'name' of the reaction. I wrote it was formation reaction
wasn't dative bonding supposed to be between N and H? :S

 

[bionology]

yes high temperature and low pressure ..didn't they ask for "TWO" conditions...

I don't think so, it was just worth 2 marks, so i first identified temp, and explained it. However, showing efficiency i mentioned the pressure thing also, lol

 

[beacon_of_light]

okey I wrote it was acid base ...lol
And btw the reaction was b/w which two species... ???

 

[bionology]

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

 

[angelgurl]

oh i forgot abt transition metals qs ya it came!!!!
ahan so tht was the isotope! the isotope is used in the reaction i guess
yr i also take bio i remembers stahl's semi conservative replication experiment in which he was using DNA and investigating it i remembered tht he used an isotope of Nitrogen dont remember which i wrote though.......so i think it could be nitrogen as well
i did codensation polymer first then i did addition because the monomer i made already had an ester bond in it and i included a c=c bond so it was some alkene with an ester group then it was easy to show cis trans isomerism
ya i know my answer was wrong i didnt conver the charge to that for 1 mole in my calculation but i did the other steps so ill get some marks in it

 

[bionology]

oh i forgot abt transition metals qs ya it came!!!!
ahan so tht was the isotope! the isotope is used in the reaction i guess
yr i also take bio i remembers stahl's semi conservative replication experiment in which he was using DNA and investigating it i remembered tht he used an isotope of Nitrogen dont remember which i wrote though.......so i think it could be nitrogen as well
i did codensation polymer first then i did addition because the monomer i made already had an ester bond in it and i included a c=c bond so it was some alkene with an ester group then it was easy to show cis trans isomerism
ya i know my answer was wrong i didnt conver the charge to that for 1 mole in my calculation but i did the other steps so ill get some marks in it

that's the semi conservation replication experiment in As biology, iam talking about the DNA fingerprinting in A2 biology
condensaiton reaction involves elimination of H20 molecule, so placing 2 OH molecules would result in the stupid polymer being made

 

[angelgurl]

That was condensation polymer I think because the functional group in the polymer was "ester" ... but when we dehydrated the polymer with Al2O3, we got a double bond i think ...
And what about the stereoisomers ... wat was the monomer...i wrote HO-CH(C2H5)-CO2H (so this compound showing optical isomerism as it was asked) and when dehydrated we get two cis-trans isomers... CH(CH3) --- CH(CO2H) Did u do like that?

i dont remember the compound but i guess when he talks about stereoisomerism it means chiral molecules so i think i went wrong because cis trans is geometrical isomerism wht do u think on this?

 

[beacon_of_light]

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

 

[angelgurl]

i know it is in AS but the thing is it can be used in the polymerase chain reaction as well because in the end all the isotope has to do is to become a part of the DNA molecule...................
the monomer could contain an ester bond in it as well

 

[beacon_of_light]

That was condensation polymer I think because the functional group in the polymer was "ester" ... but when we dehydrated the polymer with Al2O3, we got a double bond i think ...
And what about the stereoisomers ... wat was the monomer...i wrote HO-CH(C2H5)-CO2H (so this compound showing optical isomerism as it was asked) and when dehydrated we get two cis-trans isomers... CH(CH3) --- CH(CO2H) Did u do like that?

i dont remember the compound but i guess when he talks about stereoisomerism it means chiral molecules so i think i went wrong because cis trans is geometrical isomerism wht do u think on this?

Look i think first isomerism asked in the monomer E was optical while the other isomerism asked where we had to draw two structures was geometric/cis-trans...

 

[angelgurl]

whts the difference between stereo and geometrical isomerism??

 

[beacon_of_light]

i know it is in AS but the thing is it can be used in the polymerase chain reaction as well because in the end all the isotope has to do is to become a part of the DNA molecule...................
the monomer could contain an ester bond in it as well

the radioactive phosphorus attached to DNA and then darkens the X-ray film..so u can use any radioactive isotope ... but we mostly say its radioactive phosphorus

 

[angelgurl]

ahan so the alcohol was dehydrated to give cis trans isomer!!!! omg i seriously messed up in my paper

 

[beacon_of_light]

stereo is of two types : geometric and optical!

 

[bionology]

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

lol, what did others write ? both explanations make sense , wish we both could get marks

 

[beacon_of_light]

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

lol, what did others write ? both explanations make sense , wish we both could get marks

no idea about wat others wrote... but wats a formation reaction?

 

[angelgurl]

ahan!! nd how was the solution frm mining using bacteria; to b processed in order to give us copper?

 

[angelgurl]

i wrote a neutralisation reaction!!

 

[bionology]

ahan!! nd how was the solution frm mining using bacteria; to b processed in order to give us copper?

electrolysis, simple