the perfect titre......!!!!!

[mrpaudel]

my teacher got 27cm^3...and mine was 26.5!!

 

[zahraahmed]

45 people from my centre got around 26.10!!!!! and the total people were about 60. it can definitely vary from lab to lab and this the reason why examiners use the supervisors result to assess the accuracy..............

 

[zahraahmed]

ya exactly i think the range from 26-29 is the correct one...........

 

[utsav156]

yeah yeah 29.8!!! its the perfect titre !!
i got it wohoo!!!
i repeated the titration thrice in one i got 29.5 but in other two i got exactly 29.8

26.10???? one of mah got it as well!
but most of them got around 29 and 30!!!

 

[kamalrock5210]

yea i got 30.6 today..but still got the correct answer.....Damn last experiment was really confusing!

 

[utsav156]

yea i got 30.6 today..but still got the correct answer.....Damn last experiment was really confusing!

hell yeah it was!!!!

 

[maleeha123]

i was giving chem 33 and best titration value in our center was 38......................bt i got 33.1

 

[zahraahmed]

You're right, guys, but look at this way. The salt we got was Mohr's salt and 1 mol of Mohrs salt contains 14% Fe (calculated it from Wikipedia). Now, whatever the concentration of Mohr's salt maybe, it'd always contain 14% Fe and the correct titre to obtain 14% as the answer is 29.8 cm^3 given the conc. of KMn04. What can I say? I don't know how supervisors work. :|

Look guys I digged up my O levels ATP chemistry book (before giving my practical) for paper 4 of 5070 syllabus if you all can recall this code etc...
i advised everyone to go through your ATP book for this practical 33
if you look at the june 2004 paper 4 question 9 you'll find out that this is the same titration we had in paper 33 of 9701
i.e. titration of kmno4 with feso4(hydrated)
now in o levels you are provided with titres!!!!!!!!!
and the three titres given are : 25.90, 25.30,25.50
therefore at my centre 26.10 is a v.v.v.v.v.accurrate value compared to all the others reaching even till 31.00

 

[Mssamgirl15]

At our centre it was 30.00 cm^3. :/ Wth?

 

[junaidaftab]

zahraahmad, are you sure we were given hydrated iron(II) sulphate? Almost everyone is saying it was Mohr's salt

 

[hassam]

You're right, guys, but look at this way. The salt we got was Mohr's salt and 1 mol of Mohrs salt contains 14% Fe (calculated it from Wikipedia). Now, whatever the concentration of Mohr's salt maybe, it'd always contain 14% Fe and the correct titre to obtain 14% as the answer is 29.8 cm^3 given the conc. of KMn04. What can I say? I don't know how supervisors work. :|

Look guys I digged up my O levels ATP chemistry book (before giving my practical) for paper 4 of 5070 syllabus if you all can recall this code etc...
i advised everyone to go through your ATP book for this practical 33
if you look at the june 2004 paper 4 question 9 you'll find out that this is the same titration we had in paper 33 of 9701
i.e. titration of kmno4 with feso4(hydrated)
now in o levels you are provided with titres!!!!!!!!!
and the three titres given are : 25.90, 25.30,25.50
therefore at my centre 26.10 is a v.v.v.v.v.accurrate value compared to all the others reaching even till 31.00

zahra......u cnt compare with o level.....u dont know any single bit of confidentials.......the conc......of mohr salt will be different........not as that in o level

 

[Rockstar3143]

all the people in our lab got more than 35 cm3 titre..only two or three students got less than 38 others got evn more than that and a few people also had even much greater than that i.e 40 +.....................

 

[zahraahmed]

thats exactly what I'm trying to tell you guys...............the titre will vary frm lab to lab and frm session to session and this is why the examiner asks for the results of each supervisor for each session!!

 

[smj]

Yeah it does :good: :good:

 

[fireman]

i got 29.6

 

[EmptyAxis]

THE PERFECT TITRE IS approx 28.8, this is the correct titration for those whose centres followed the procedure properly!!!!!!!! :Bravo: :crazy:

 

[xHazeMx]

29.8 cm*3......those who got this are in dreamland,,,,others in HELL.....this calculation will lead to exact percentage of fe2+ in mohr salt

GREAT ! I GOT 29.75 cm*3 .. :Yahoo!: