Edexcel IAL chemistry unit 6B 16/5/2017 exam thread

Reply 40

hasi.99

4

Jan 2017 unit 6 is messed up! I dont know what to expect this time!

Reply 41

Bliss_

9

Original post by pondsteps

wtf is this june 2016 paper??!!! did anyone attempt it ???? i was solving all the papers and everything was going fine now i solved that paper and i feel so depressed and unready for the exam!!! ughhhhhh i neeed help with it

exactlyidk what to do either.
after solving jan17 and june 16 im just so depressed idk what to do :frown:

Reply 42

shady zax

4

ImageUploadedByStudent Room1494825886.572777.jpg

Could somebody please explain the answer of b to me? 😢

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Reply 43

alevels2k17

OP

14

Original post by shady zax

Could somebody please explain the answer of b to me? 😢

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is this unit 6 chem or unit 4 :K:

which year is it??

Reply 44

alevels2k17

OP

14

Original post by shady zax

Could somebody please explain the answer of b to me? 😢

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isnt the answer cos reaction 1 is the rate determining step

Reply 45

shady zax

4

Original post by pondsteps

isnt the answer cos reaction 1 is the rate determining step

If u combine the last two equations u get the equation in 1..so..?

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Reply 46

hiyoriiki183

Probably so that the iodate and hydrogensulfate have a chance of participating in reactions 2 and 3
If reaction 1 was too fast then they would be completely used up😫😫😫 I hope

Reply 47

dr-jekyll

Original post by shady zax

Could somebody please explain the answer of b to me? 😢

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I think it's because both IO3- and HSO3- should be in the rate determining step and reaction 1 is the only reaction where they are both present as reactants.

I'm not completely sure though so if you find out the answer please do let me know.

Reply 48

cool99w

2

Part ( c)

why isn't the color change from colorless to pink
since the Kmno4 i added to the Fe solution

Screen Shot 2017-05-15 at 3.20.42 PM.png58.4KB

Reply 49

cool99w

2

This too??? why shouldn't it be colorless to pink
since KMNo4 is added to Glucosee

Screen Shot 2017-05-15 at 3.22.50 PM.png19.2KB

Screen Shot 2017-05-15 at 3.22.47 PM.png97.2KB

Reply 50

shady zax

4

Original post by hiyoriiki183

Probably so that the iodate and hydrogensulfate have a chance of participating in reactions 2 and 3
If reaction 1 was too fast then they would be completely used up😫😫😫 I hope

The answer is to avoid the formation of the black colour too soon..wats that mean?

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Reply 51

shady zax

4

Original post by dr-jekyll

I think it's because both IO3- and HSO3- should be in the rate determining step and reaction 1 is the only reaction where they are both present as reactants.

I'm not completely sure though so if you find out the answer please do let me know.

Huh? 😢

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Reply 52

shady zax

4

Original post by cool99w

This too??? why shouldn't it be colorless to pink
since KMNo4 is added to Glucosee

It should be pink to colourless ..i think.. Purple manganate is reduced to mn2+ by the glucose... As this only gradually happens purple solution gradually gets paler until at the end point the last of the mno4- is converted to colourless mn2+

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Reply 53

shady zax

4

Does anybody know the identity of the black ppt from an unsuccessful positive silver mirror test?

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Reply 54

Willandy123

7

Where can I find the jan 2017 paper?

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Reply 55

cool99w

2

Original post by shady zax

It should be pink to colourless ..i think.. Purple manganate is reduced to mn2+ by the glucose... As this only gradually happens purple solution gradually gets paler until at the end point the last of the mno4- is converted to colourless mn2+

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But you are adding the mno4 to the flask which contains glucose