Chem.p34 answer discussion...

[FurqanKhalil]

Did anyone draw and fill their titration tables with a pencil. Is it allowed?

 

[Soulgamer]

The titre value for step 1 was : 15.70 cm3
The titre value for step 2 was: 15.30 cm3

for both titrations almost the same..

Im sorry thats not possible

 

[mariamalik]

This is scary i mean ,Y is every1s titration value different ? it should almost be the same. Just leave it to Allah and Hope for the best.

 

[Saad (سعد)]

The titre value for Step 1 in by my Centre's Supervisor was 17.00 cm3, and for Step 2 was 22.20 cm3.

I got 17.00 cm3 down accurately for the first step, but got 23.25 cm3 for the second one.

How many marks will I lose?

 

[Bulltyro]

guys my titre vales were like 14 and 19.9
what do you think?

 

[angelgirl:)]

omg u okay ??

yes ALhamdullilah...alright...

 

[angelgirl:)]

The titre value for step 1 was : 15.50 cm3
The titre value for step 2 was: 22.55 cm3

The percentage by mass : 43% but don't worry, whosoever attempted this part will be given full marks as there was a misprint in the paper for the formula given.

The non metal was Nitrogen.

Fe2+ was in FB9.

The last part of salt analysis was that if KMnO4 was added to FB9, what happened.
You could write:
1) Colour change from purple to colourless.
2) Fe2+ will be oxidized to Fe3+ so red-brown ppt will be formed.

i no they wrote wrong formula...so i wrote the structural formula for my calculation...in 1 formula they give 2 O and in the other 1 they give 4 "O"....

 

[saudha]

my titre values wer step 1 : 15.8
step 2 : 22.4

 

[saudha]

What was the answer for the last two parts of titration?
The part which talked abt pipette n burette measuring 25cm3?
N also what were the observations for the anion test?

....i calculated the % error for pipette and burette and compared % error, for pipette was higher and the q was, one student did titration in a pipette instead of a burette so is it right? the answer was definately no...

 

[Anonymous stranger]

The titre value for step 1 was : 15.50 cm3
The titre value for step 2 was: 22.55 cm3

The percentage by mass : 43% but don't worry, whosoever attempted this part will be given full marks as there was a misprint in the paper for the formula given.

The non metal was Nitrogen.

Fe2+ was in FB9.

The last part of salt analysis was that if KMnO4 was added to FB9, what happened.
You could write:
1) Colour change from purple to colourless.
2) Fe2+ will be oxidized to Fe3+ so red-brown ppt will be formed.

Dude al my answers match yours except %mass and thts 73 % if you take the misprint.

 

[Soulgamer]

Our supervisor said that all of us will given marks for this particular part if anybody has attempted it correctly.

 

[Soulgamer]

Due to the misprint i.e.

 

[Anonymous stranger]

Guys In the observations for anions in the table did you write observations fer each step or just what you saw in d end like in the step where u had to add kmno4 and then fb6 did u write colour change frm colourless to pink and then from pink to colourless when u add fb6 or just frm pink to colourless.???? Cause it was mentioned in the begging, show clearly when a change takes place in each step. Man I'm damned worried pls someone reply quick!!!!

 

[Beaconite]

What do you guys think the threshold will be for p34? Because alot of people I know weren't happy with it and had missed stuff, especially in Q2.

 

[Saad (سعد)]

What do you guys think the threshold will be for p34? Because alot of people I know weren't happy with it and had missed stuff, especially in Q2.

Let's just pray that its below 25. o-o

 

[abdullahsatar]

The paper was tough and too long, I wanted to ask that what if I left the last three calculations parts for question one about the percentage etc. also, though I'm pretty sure my titre volume was correct, but what if my second titre volume is a bit more or less than that of the supervisor's. How much do you guys think I might lose? Provided that I did the calculations correctly?

 

[Beaconite]

I hope so. The way papers have went, I'd say it won't be higher than 27.

 

[Beaconite]

I think the rule is that you get full marks if the deviation in average volume is not more than 0.3 cm3, 1 mark loss if the deviation is between 0.3-0.6 and 2 mark loss if more than that.

 

[Ammirul Shafiq]

Im sorry thats not possible

why not possible?it is an experiment right?and he gt the reading already. ;p

 

[Anonymous stranger]

Guys In the observations for anions in the table did you write observations fer each step or just what you saw in d end like in the step where u had to add kmno4 and then fb6 did u write colour change frm colourless to pink and then from pink to colourless when u add fb6 or just frm pink to colourless.???? Cause it was mentioned in the begging, show clearly when a change takes place in each step. Man I'm damned worried pls someone reply quick!!!!

Guys Plz answer!!!