* Chemistry * Predictions / discussion / aftermath * (1 thread please)

partyatmygaff

Chris Martin wrote: »

Went to UCC lecture and they said chances of Ethanol/Ethanal/Ethanoic Acid were probably not going to come up and they're taking it off the Mandatory Practical Experiment Course next year as Chemicals in their solid forms are seen to be dangerous when airborne.
What I heard anyway...
Wouldn't put money on it but he sounded pretty certain.

Well i'm equally certain that they will come up. They're extremely important experiments on our Organic Chemistry course and considering we're the last year examinable on those experiments it seems very likely that one will come up.

King Kenny

What are those box thingys called where you show Hund's theory for orbitals (1Px 1Py 1Pz)?

._.

cobear wrote: »

I'm really hoping that fuels etc comes up especially after the BP oil spill - as some other poster said. Any ideas if you have to know the rough amount of carbons and boiling points for each fraction or is knowing the names, examples and uses enough?

But that comes up every year in Q6 O_o

DM360

King Kenny wrote: »

What are those box thingys called where you show Hund's theory for orbitals (1Px 1Py 1Pz)?

Orbitals? Electronic configurations? I don't think the boxes themselves have names

cobear

._. wrote: »

But that comes up every year in Q6 O_o

Oh yeah I know it does I was just wondering how much detail you'd need!

seanh12

Right lads I've one day left to study for this.. What should I focus on?

._.

seanh12 wrote: »

Right lads I've one day left to study for this.. What should I focus on?

Passing :pac:

seanh12

Im obviously gona pass it I got a b2 in the mocks :P But like what topics should I have a look over tomorrow?

aranciata

Would it be alright at this stage to leave out saponification and recrystallisation of benzoic acid? (both came up last year)

Also thinking of leaving out the analysis techniques - spectroscopy, chromatography etc.

YodaBoy

seanh12 wrote: »

Im obviously gona pass it I got a b2 in the mocks :P But like what topics should I have a look over tomorrow?

know the experiments and do all the Q4s to get a good overview

YodaBoy

aranciata wrote: »

Would it be alright at this stage to leave out saponification and recrystallisation of benzoic acid? (both came up last year)

Also thinking of leaving out the analysis techniques - spectroscopy, chromatography etc.

I wouldn't have a clue if one of last years expts came up myself but I think Chromatography and instrumentation is strongly tipped...maybe for 25marks in Q10..

DM360

Just wondering but does everybody else do all 3 experiments in Section A? Everyone in my class does it because our teacher told us to but just want to see what everyone else does

partyatmygaff

DM360 wrote: »

Just wondering but does everybody else do all 3 experiments in Section A? Everyone in my class does it because our teacher told us to but just want to see what everyone else does

Why wouldn't you? All the paper asks of you is to answer eight questions with at least two from section A.

River Song

DM360 wrote: »

Just wondering but does everybody else do all 3 experiments in Section A? Everyone in my class does it because our teacher told us to but just want to see what everyone else does

I did it once, was the worst test I did. But that's just me. I usually do Q1,2,4,6,7,9,10,11. I've done like...15+ papers fully, as in sat for 3 hours etc. and always done that combination, maybe deviating once or twice. But usually those questions lol. Wherever acid/bases are, I'll go!

jumpguy

partyatmygaff wrote: »

Well i'm equally certain that they will come up. They're extremely important experiments on our Organic Chemistry course and considering we're the last year examinable on those experiments it seems very likely that one will come up.

Also, the exams were most likely prepared before hexavalent compounds (dichromate, chromate) were banned in school labs. We heard about the ban in February/March, but the papers were most likely completed by late last year.

Jaafa

Any one else absolutely hate/gona skip question 8? (that is the one with reactions between OC?)

mk6705

Jaafa wrote: »

Any one else absolutely hate/gona skip question 8? (that is the one with reactions between OC?)

Leaning towards doing that one...It's easy enough if you learn it for about half an hour...

Jaafa

Adro947 wrote: »

Leaning towards doing that one...It's easy enough if you learn it for about half an hour...

I don't know i found it very varied. I mean they can draw from 3 chapters for that question.

Gavarn

Jaafa wrote: »

Any one else absolutely hate/gona skip question 8? (that is the one with reactions between OC?)

I'm avoiding it! Near failed my mocks cause I thought I'd be ok doing that question so neglected the acid-base Q and wasted my time on that.

cxh20y

Hey Lads, just wondering do any of ye know if there are any other diatomic molecules like oxygen and nitrogen that have more than one bond? i.e for Nitrogen there are three bonds between the molecule N=N (should be another bond in there) and Oxygen O=O ? I'm pretty sure Chlorine has only one bond between its molecules.

partyatmygaff

cxh20y wrote: »

Hey Lads, just wondering do any of ye know if there are any other diatomic molecules like oxygen and nitrogen that have more than one bond? i.e for Nitrogen there are three bonds between the molecule N=N (should be another bond in there) and Oxygen O=O ? I'm pretty sure Chlorine has only one bond between its molecules.

There's no need to learn it off. Just check the periodic table and work it out from there.

Gavarn

Just wondering, there has not been a full question on electrochemistry since 2001. Has it been taken off the exam paper or could it come up?

partyatmygaff

Gavarn wrote: »

Just wondering, there has not been a full question on electrochemistry since 2001. Has it been taken off the exam paper or could it come up?

It hasn't been taken off but the SEC rarely seem to think it warrants an entire question to itself. They usually put it in as a short question or a part a,b,c of Q11.

cxh20y

How do you figure it out by just looking at the periodic table?

Sm4shbox

Lads, just wondering in relation to BLEACH.
Why do you use sulfuric acid and not...
1) Nitric acid?
2) HCL acid?


Thank'ya!

partyatmygaff

Sm4shbox wrote: »

Lads, just wondering in relation to BLEACH.
Why do you use sulfuric acid and not...
1) Nitric acid?
2) HCL acid?


Thank'ya!

Nitric acid itself is an extremely powerful oxidising agent.
The CL ions would interfere with the reaction.

Gavarn

Looking over the bleach experiments that came up in the examcraft mock paper and it asks to show how the 50cm^3 sample of bleach was diluted in 500cm^3.. In our lab there are only 250 volumetric flasks, so is there a flask that does 500 or do you have to split it? Stupid question probably but I want to be sure! Thanks

crazylegskane

Any tips for ordinary paper?
Experiments wise

._.

Gavarn wrote: »

Looking over the bleach experiments that came up in the examcraft mock paper and it asks to show how the 50cm^3 sample of bleach was diluted in 500cm^3.. In our lab there are only 250 volumetric flasks, so is there a flask that does 500 or do you have to split it? Stupid question probably but I want to be sure! Thanks

Yeah there are 500cm^3 flasks

partyatmygaff

._. wrote: »

Yeah there are 500cm^3 flasks

There are also [LATEX]1000cm^3[/LATEX] and beyond. Standard sizes are 100, 250, 500, 1000, 1500, 2000, 3000, 5000.