How was Chemistry P42

[Evil_Maknae]

anyway! for the DNA fingerprinting question? which suspect was arrested?

I think I wrote suspect 1... You?

 

[Nishii]

I think I wrote suspect 1... You?

me too! because his fingerprints were found in both rooms, as for the electrochemistry part, i doubt my answers!

 

[Evil_Maknae]

me too! because his fingerprints were found in both rooms, as for the electrochemistry part, i doubt my answers!

I wrote the same reason too *high five*

You got what for the Ksp and the [Ag+] ?

 

[Nishii]

I wrote the same reason too *high five*

You got what for the Ksp and the [Ag+] ?

dont remember, for Ksp i did [Ag+]^3!

 

[Evil_Maknae]

dont remember, for Ksp i did [Ag+]^3!

Haha reallly?

Remember any other question?

 

[Nishii]

Haha reallly?

Remember any other question?

yeah didnt know what conc of SO4^2- to take, i assumed to be the same as Ag+!==
the nmr question, i got CH3C=OOCH2CH3,
the homogeneous catalysis question i wrote the reactions between I- and S2O8^2-, heterogeneous --> haber process!
i dont remember more than that!! xP

 

[good man12]

for copper mass i am 99% confirmed it was 2.86 gramzzzzz

 

[Nishii]

for copper mass i am 99% confirmed it was 2.86 gramzzzzz

you remember your calculations?

 

[good man12]

you remember your calculations?

conc of Fe2+ ions was 0.6 mol per dm, in begining of ques they gave us that solution has conce of 1.5 mol dm of Fe 3+, the equation showed that Fe 3+ reacts with copper only, so then conce of Fe 3+ in solution when o.6 moles of Fe 2+ has formed = 1.5-0.6=0.9, since it was 100cm cubed, moles are 0.09, copper reacts in 1:2 ratio, so 0.045 moles, 0.045x63.5= 2.86g

 

[Evil_Maknae]

conc of Fe2+ ions was 0.6 mol per dm, in begining of ques they gave us that solution has conce of 1.5 mol dm of Fe 3+, the equation showed that Fe 3+ reacts with copper only, so then conce of Fe 3+ in solution when o.6 moles of Fe 2+ has formed = 1.5-0.6=0.9, since it was 100cm cubed, moles are 0.09, copper reacts in 1:2 ratio, so 0.045 moles, 0.045x63.5= 2.86g

I think we has to use the concentration of the partially used solution and not the original concentration

 

[good man12]

I think we has to use the concentration of the partially used solution and not the original concentration

yes, i used the "partially used" solution, only 0.9 moles of Fe 3+ were left, i know many candidates did calculations wit o.6mol dm conce of Fe 2+, but on second thought, does Fe2+ even react with copper!!!!!

 

[Evil_Maknae]

yes, i used the "partially used" solution, only 0.9 moles of Fe 3+ were left, i know many candidates did calculations wit o.6mol dm conce of Fe 2+, but on second thought, does Fe2+ even react with copper!!!!!

It said in the question that the Mn04- ions reconverted the Fe2+ left to Fe3+ and that was the partially used solution

 

[caro24]

conc of Fe2+ ions was 0.6 mol per dm, in begining of ques they gave us that solution has conce of 1.5 mol dm of Fe 3+, the equation showed that Fe 3+ reacts with copper only, so then conce of Fe 3+ in solution when o.6 moles of Fe 2+ ha

yes, i used the "partially used" solution, only 0.9 moles of Fe 3+ were left, i know many candidates did calculations wit o.6mol dm conce of Fe 2+, but on second thought, does Fe2+ even react with copper!!!!!

s formed = 1.5-0.6=0.9, since it was 100cm cubed, moles are 0.09, copper reacts in 1:2 ratio, so 0.045 moles, 0.045x63.5= 2.86g

did u remember how many marks was this question?did u?????

 

[berry89th]

how did you do it? first i got 0.0048g then i manipulated it again and got 3.81 or something :/

mee too, i got the same...

 

[berry89th]

yeah didnt know what conc of SO4^2- to take, i assumed to be the same as Ag+!==
the nmr question, i got CH3C=OOCH2CH3,
the homogeneous catalysis question i wrote the reactions between I- and S2O8^2-, heterogeneous --> haber process!
i dont remember more than that!! xP

i took conc of SO4^2- half of Ag+ and did it, and for the rest i got same result as yours

 

[Nishii]

did u remember how many marks was this question?did u?????

1 mark!

 

[Nishii]

i took conc of SO4^2- half of Ag+ and did it, and for the rest i got same result as yours

i did what you did first, then i crossed it out