• We need your support!

    We are currently struggling to cover the operational costs of Xtremepapers, as a result we might have to shut this website down. Please donate if we have helped you and help make a difference in other students' lives!
    Click here to Donate Now (View Announcement)

Chem.p34 answer discussion...

Messages
39
Reaction score
6
Points
18
This is scary i mean:unsure: ,Y is every1s titration value different ? it should almost be the same. Just leave it to Allah and Hope for the best. (y)
 
Messages
224
Reaction score
183
Points
53
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?
 
Messages
532
Reaction score
151
Points
53
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"....
 
Messages
198
Reaction score
47
Points
28
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...
 
Messages
24
Reaction score
6
Points
3
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.
 
Messages
462
Reaction score
166
Points
53
Our supervisor said that all of us will given marks for this particular part if anybody has attempted it correctly. :)
 
Messages
24
Reaction score
6
Points
3
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!!!!
 
Messages
20
Reaction score
3
Points
13
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.
 
Messages
13
Reaction score
1
Points
13
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?
 
Messages
20
Reaction score
3
Points
13
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.
 
Messages
24
Reaction score
6
Points
3
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!!!
 
Top