chemistry practical 32 discussion

[anushey]

how was the practical???what was the decrease in concentration of iron(iii)chloride?i got 1.67*10^3
or were we meant to subtract it?

 

[Enas Alhaje]

Yes . Mines was 0.0483 moldm^-3 . How was the paper overall ? it was an exact replicate of w2012 variant 35 :O

 

[PoIsOngAlLeRy]

Yes . Mines was 0.0483 moldm^-3 . How was the paper overall ? it was an exact replicate of w2012 variant 35 :O

yea..i got tht too buh i kinda rounded it to 0.050...i lovd it

 

[ayhammad]

i got the decrease in iron concentration 9.14x10^-5, how did u get ur results ?

 

[anushey]

gyes i got the concentration as 1.67 *10^3 for the concentration.if this is wrong then my wrong next question and the graph will also get wrong/how much marks will i lose...any idea?i didnot substract it from 0.05 becuz otherwise the rate would have gone to 1000 so i was confused.

 

[anushey]

Yes . Mines was 0.0483 moldm^-3 . How was the paper overall ? it was an exact replicate of w2012 variant 35 :O

so was your rate coming in 1000s .i didnt subtract the answer from 0.05.r u sure of yr answer

 

[asexamskillme111]

i got the decrease as 0.00167 too.

 

[Enas Alhaje]

so was your rate coming in 1000s .i didnt subtract the answer from 0.05.r u sure of yr answer

yes,quite sure . and they were in 1400 1600 , till 2000.
I'm not very sure if we can discuss the paper right now though xD

 

[asexamskillme111]

lol dude that's way too high..2000 mol.dm-3 per second?!
i doubt it. they even said we would have to use a value around 2.25 x10-3 if we don't get the answer. 0.0485 is way too high.
i think if we had to subtract it from something they would also tell us to use the information shown opposite along with use the answer in (iii)

 

[Enas Alhaje]

lol dude that's way too high..2000 mol.dm-3 per second?!
i doubt it. they even said we would have to use a value around 2.25 x10-3 if we don't get the answer. 0.0485 is way too high.
i think if we had to subtract it from something they would also tell us to use the information shown opposite along with use the answer in (iii)

What was your value then ?

 

[asexamskillme111]

my decrease was 0.00167..i have a feeling i messed up though.
my rates ranged from around 0.000113 to like 0.000180. i found it kinda hard to believe that it would decrease by THAT much in one second so i stuck with those values.

 

[Enas Alhaje]

There's no other way to do it . I dont believe its wrong , because some people at my centre got the same answer. Anyhow , let's say its wrong , how many marks would I lose?

 

[Enas Alhaje]

but that's too low too ^^ Hmm, Im confused now :/

 

[asexamskillme111]

Yea there was a guy who got your answer at my centre too. I think you'd lose a max of 1-2 marks. Even if you took the value they gave you and you weren't able to calculate it you'd only lose a max of 2 and here there's an actual attempt so yea. My answer is probably wrong though. Story of my life haha.

 

[asexamskillme111]

I don't think they're too low. It took around 89 seconds for the blue black colour to appear with 20 cm3 of FB1. If it was gonna decrease by around 2000 it wouldn't take 89 seconds /:

 

[pearl angel]

i was unable to get a correct decrease in concentration so i used the one they gave us...how many marks would i loose??:/

 

[Enas Alhaje]

that's tooo high ! in our centre it ranged from 25 to 35 and 35 was the maximum . I personally got 25 . its very concentrated so this would take less time then the 10cm^3 one . What did you get for that then :O

 

[asexamskillme111]

i was unable to get a correct decrease in concentration so i used the one they gave us...how many marks would i loose??:/

the whole calculation part was like 3 marks so i think you would only lose 2 worst case scenario

 

[asexamskillme111]

that's tooo high ! in our centre it ranged from 25 to 35 and 35 was the maximum . I personally got 25 . its very concentrated so this would take less time then the 10cm^3 one . What did you get for that then :O

people at my centre got around the same times.
for the second experiment a couple of guys and i all got 126 seconds. DAFUQ. :|

 

[pearl angel]

the whole calculation part was like 3 marks so i think you would only lose 2 worst case scenario

but i used that value to calculate rate of reaction for the graph...wouldn't my marks get deducted??