This discussion is closed.
Unregistered
Badges:
#1
Report 16 years ago
#1
1/ Describe a procedure wherby a standard solution of potassium manganate may be used to estimate the concentration of an iron(II) Sulphate solution.

(b) In such an experiment 22.50 CM3 of 0.0200 mol dm-3 aqueous potassium manganate(VII) KMnO4 was required to oxidise 25.0cm3 of aqueous IRON(II) Sulphate, FeSo4.

(i) Write half equations for
The oxidation of the iron(II) ion, Fe2+

the reduction of the manganate(VII)ion, MnO4- in acidic solution.

(III) Calculate the concentration of the IRON(II) Sulphate solution.

(5a)Name the type of reaction occuring with [Cr(H2O)6]3+ with EXCESS NH3.

(5e) state with reasons the number of peaks in the NMR spectra of propanone and propanal.
0
Vin
Badges:
#2
Report 16 years ago
#2
How come you get the Chem papers to keep? I never get to keep any of my exam papers in any subject.

In response to your questions:

1) Pipette a known volume of iron (II) sulphate solution into a conical flask and add excess dilute sulphuric acid. Fill a burette with a known concentration of potassium manganate (VII) and run in until there is a faint pink colour (minute excess of MnO4- ions).

- I remembered I wrote a bit more than that since it was worth like 5 marks.

b) i) Fe2+ --> Fe3+ + e-
MnO4- + 8H+ +5e- --> Mn2+ + 4H2O

- I got something like 0.09 mol dm^-3 as my final answer for the concentration.

5a) Ligand exchange.

- However, I suspect that the question had an unnoticed erratum since, there should not be any further reaction with excess NH3. This only occurs with excess OH. Anyway.

e) Propanone: 1 peak, only a -CH3 group. Propanal: 3 peaks, 3 groups -CH3, -CH2, and -COH.
0
Unregistered
Badges:
#3
Report 16 years ago
#3
Vin
u seem to have MAKE THE GRADE NAS CHEMISTRY
0
Unregistered
Badges:
#4
Report 16 years ago
#4
Originally posted by Unregistered
Vin
u seem to have MAKE THE GRADE NAS CHEMISTRY
Correct, haha. I wrote the response to 1) nearly verbatim from the book since I don't recall what I wrote that day.
0
Vin
Badges:
#5
Report 16 years ago
#5
The above post was by me.
0
X
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Regarding Ofqual's most recent update, do you think you will be given a fair grade this summer?

Yes (80)
27.4%
No (212)
72.6%

Watched Threads

View All