Aburumman.. what was the planning question? What exactly came out? What about the rest of the paper?? please share... I'll be sitting for my practical tmrw... Group2

Reply 5

ArVi

This has been one of the easiest practicals I've ever done :biggrin:

Reply 6

"Hurricane"

POLL: How did you do in your EDEXCEL Physics A2 Practicals?
http://www.thestudentroom.co.uk/showthread.php?t=232025

Reply 7

"Hurricane"

That is true.
But the candidate slip was of great help though. I dont know why doesnt our school mention anything about it and the user guide!!

Reply 8

meee82

hey guys what were you asked in the exam??????

Reply 9

Smashingdude

Very good indeed. The first was after all Fe+2 ions. And I just dont know i got so accurte boiling point. exactly 77. Strange but its correct. I confirmed with the teacher and says its excellent.
The easiest practical so far. HELL they gave KCl to identify.................

Reply 10

urban_flavaz

so what was the plan about? was it aluminium, zinc and ammonia? hey, if u have ammonia hw wud u identify it as ammonia? i dont get it.. :confused:

Reply 11

ArVi

Smashingdude

The first was after all Fe+2 ions.

My solid and solution were both yellow :confused:

Will I lose marks for writing "possible Fe3+" as the inference for question 1?

Reply 12

"Hurricane"

Well, for group 2 people, here are the questions:
Question 1:
Part A: Identify Fe2+. We did precipitation and oxidisation (H2O2) on it. We also used BaCl2 to identify SO4 2-.
Part B: Identify K+ by flame test and Cl- by pptation with AgNO3.

Question 2:
Part A: We did 2,4 DNP test, then we did Fehling's test, to identify aldehyde. We were then given mass spectrum analysis, result was propanal.
Part B: We did esterification to identify an alcohol. We then did oxidation by dichromate on it, result was positive, thus, it was a 1 or 2 degree. We were then given that it contains 1 more carbon than propanal, we drew the structure of the 2 isomers. Then we wre asked to write the reagents used to identify the isomers, I used the Iodoform.

Question 3:
We were asked to measure bp, I got 76 for rising and 77 for fall, thus the compound was ethyl ethanoate, inaccuracy was because bp values of compounds are close (difference of 2 degrees only), one source of inaccuracy was poor conductivity of water, improvement was by using fractional distillation.

Question 4:
Part A: Identifying 3 compounds (AlCl3, ZnCl2, NH3)=>EASY
Part B: Seperate between a mixture of ZnCl2 and AlCl3, you should get Zn2+ ions => Use simple filteration, Zn2+ as filterate.

Hope this helps group 1 and 2 ppl.
Good luck group 2.
I have my next exam on 15th of june, so im ready to help.

Reply 13

"Hurricane"

urban_flavaz

so what was the plan about? was it aluminium, zinc and ammonia? hey, if u have ammonia hw wud u identify it as ammonia? i dont get it.. :confused:

You are given NaOH, so it precipitates both Al and Zn, but not NH3.
Remember all NH3 salts are water soluble.

Reply 14

"Hurricane"

ArVi

My solid and solution were both yellow :confused:

Will I lose marks for writing "possible Fe3+" as the inference for question 1?

I guess for question 1, yeah. Cuz you arent supposed to identify it, you just have to say its a water soluble salt, not to mention you got it wrong :frown:

Reply 15

urban_flavaz

thank u sooo much! one thing tho bout planning...
do u add NaOH to all 3 samples first? so u get white ppt wid aluminium and zinc but what wud u get wid NH3 aq?

Reply 16

"Hurricane"

urban_flavaz

thank u sooo much! one thing tho bout planning...
do u add NaOH to all 3 samples first? so u get white ppt wid aluminium and zinc but what wud u get wid NH3 aq?

It remains colourless with NH3. Remember all (NH3)+ salts are water soluble. :smile:

Reply 17

ajcool

Aburumman

Question 2:
Part A: We did 2,4 DNP test, then we did Fehling's test, to identify aldehyde. We were then given mass spectrum analysis, result was propanal.
Part B: We did esterification to identify an alcohol. We then did oxidation by dichromate on it, result was positive, thus, it was a 1 or 2 degree. We were then given that it contains 1 more carbon than propanal, we drew the structure of the 2 isomers. Then we wre asked to write the reagents used to identify the isomers, I used the Iodoform.

Question 3: We were asked to measure bp, I got 76 for rising and 77 for fall, thus the compound was ethyl ethanoate, inaccuracy was because bp values of compounds are close (difference of 2 degrees only), one source of inaccuracy was poor conductivity of water, improvement was by using fractional distillation.

QUOTE]

hey you know for ques 2 b) do you remeber the exact question, ??
anyway you know when you added the sodium carbonate and all that, and then you got fizzing and bubbles, did you identify that as the caarboxylic acid?