****Leaving Certificate Chemistry [All Levels] Before and After Discussion****

Julius Seizure

MacBizzle wrote: »

Or you can just do rise over run, doesn't really matter.

They're the same thing no? Rise is the difference in heights (y2-y1) and run is x2-x1

MacBizzle

Julius Seizure wrote: »

They're the same thing no? Rise is the difference in heights (y2-y1) and run is x2-x1

Yes they are, but rise over the run is quicker than plotting points and all that

booblefoop

MacBizzle wrote: »

Yes they are, but rise over the run is quicker than plotting points and all that

But how do you find rise over run without plotting points?

MacBizzle

booblefoop wrote: »

But how do you find rise over run without plotting points?

I just count it, thinking about it now I've just been doing it the same way without realising it

booblefoop

MacBizzle wrote: »

I just count it, thinking about it now I've just been doing it the same way without realising it

Yeah, same method, just different names :P

little sis...

little sis... wrote: »

What is it exactly that we need to know about chromotography?

Anyone know? :rolleyes:

MacBizzle

little sis... wrote: »

Anyone know? :rolleyes:

Not me, please tell us someone :pac:

chatterboxxx95

little sis... wrote: »

Anyone know? :rolleyes:

Eh what it is
A seperation technique in which a mobile phase moves in contact with a selectively absorbant (may be adsorbant, not sure) stationary phase and seperation is brought about by different components in the mixture having different interactions with the mobile and stationary phases

-how to carry out one type of chromatography (eg the jc paper chromatography)

-how Gas Chromatography works

-How high perfornance liquid chromatography works

deadpixel

little sis... wrote: »

Anyone know? :rolleyes:

Seems fairly skippable to be honest, never really liked it as a topic so I think I'll steer clear. Nice thing with chemistry is the decent amount of choice on the paper, especially if you do 3 experiments.

Peter Flynt

I'm going for the following first three questions in tomorrow's paper.

Q1 - Ammonium Iron(II) Sulfate-Potassium Manganate(VII) Titration
Q2 - Preparation of Soap
Q3 - Decomposition of Hydrogen Peroxide (Rates) using Manganese Dioxide

I teach Chemistry btw

BauBau19

Peter Flynt wrote: »

I'm going for the following first three questions in tomorrow's paper.

Q1 - Ammonium Iron(II) Sulfate-Potassium Manganate(VII) Titration
Q2 - Preparation of Soap
Q3 - Decomposition of Hydrogen Peroxide (Rates) using Manganese Dioxide

Hmm. Hopefully something like that. Don't really like the Ammonium Iron one .

I got 70% in the mocks but I knew the topics coming up... absolutely dreading it now.

MacBizzle

Peter Flynt wrote: »

I'm going for the following first three questions in tomorrow's paper.

Q1 - Ammonium Iron(II) Sulfate-Potassium Manganate(VII) Titration
Q2 - Preparation of Soap
Q3 - Decomposition of Hydrogen Peroxide (Rates) using Manganese Dioxide

This would be lovely. I hope to get full marks on the experiment questions, doing all 3 of them.

I have all of organic to revise now for the next 3 hours I hate question 8.

little sis...

chatterboxxx95 wrote: »

Eh what it is
A seperation technique in which a mobile phase moves in contact with a selectively absorbant (may be adsorbant, not sure) stationary phase and seperation is brought about by different components in the mixture having different interactions with the mobile and stationary phases

-how to carry out one type of chromatography (eg the jc paper chromatography)

-how Gas Chromatography works

-How high perfornance liquid chromatography works

Do we need to know anything about the other methods of carrying out the expt?

My definitions for it is : a separation of a mixture of components based on their relative attractions for a stationary phase and/or a mobile phase.
I just learned it off from the marking scheme so hopefully that will always be accepted.

Daniel2590

Has anyone's teacher given them predictions for the experiments or even just a few to focus on that are likely? Our teacher is fairly useless…

plmko

Am I the only leaving cert who absolutely loves origanic chemistry?

CiaraMT

chatterboxxx95 wrote: »

Eh what it is
A seperation technique in which a mobile phase moves in contact with a selectively absorbant (may be adsorbant, not sure) stationary phase and seperation is brought about by different components in the mixture having different interactions with the mobile and stationary phases

-how to carry out one type of chromatography (eg the jc paper chromatography)

-how Gas Chromatography works

-How high perfornance liquid chromatography works

I think its adsorbent

A7XGirl

plmko wrote: »

Am I the only leaving cert who absolutely loves origanic chemistry?

I know right! It's the only part that comes easy to me

MacBizzle

Are we meant to know VSEPR theory for molecules with double bonds?

plmko

A7XGirl wrote: »

I know right! It's the only part that comes easy to me

Damnnn that cyclic bromium ion

MacBizzle wrote: »

Are we meant to know VSEPR theory for molecules with double bonds?

Most definitely;

Examples include water and ammonia. Water being v shaped and ammonia being pyramidal due to the double bonds which push down the single bonds.

MacBizzle

plmko wrote: »

Most definitely;

Examples include water and ammonia. Water being v shaped and ammonia being pyramidal due to the double bonds which push down the single bonds.

Water and ammonia have single bonds? are you thinking of lone pairs and bond pairs maybe?

football girl

Don't leave out any experiments as they could give a mixed question like last year! Caught a lot of us out

accountname

Quick question; for the calculations on the auld titrations, if they give us three figures for volume, do we always discount the first as a rough titration and get the mean of the other two?

little sis...

accountname wrote: »

Quick question; for the calculations on the auld titrations, if they give us three figures for volume, do we always discount the first as a rough titration and get the mean of the other two?

Yes.

plmko

MacBizzle wrote: »

Water and ammonia have single bonds? are you thinking of lone pairs and bond pairs maybe?

Christ you're right I'm so sorry! What was your original question?

MacBizzle

plmko wrote: »

Christ you're right I'm so sorry! What was your original question?

You're grand :pac:

Do we need to know VSEPR theory for molecules with double bonds? Like CO2 and stuff?

little sis...

MacBizzle wrote: »

Are we meant to know VSEPR theory for molecules with double bonds?

Never even crossed my mind. So I guess not :P

BlueCat01

For ordinary level chemistry, what organics groups and isomers do we need to know?
Our teacher taught us all higher level and never differentiated between higher and ordinary!

Julius Seizure

BlueCat01 wrote: »

For ordinary level chemistry, what organics groups and isomers do we need to know?
Our teacher taught us all higher level and never differentiated between higher and ordinary!

Here's the link to the syllabus. It's a PDF direct download by the way https://www.education.ie/en/Schools-Colleges/Information/Curriculum-and-Syllabus/Senior-Cycle-/Syllabuses-and-Guidelines/lc_chemistry_sy.pdf

robman60

Hi guys,

I'm going to have to cram desperately tonight, as I've neglected this subject completely.

If you were to advise me to study four experiments, what would they be? What other sections should I definitely cover in the limited time I have left? I'm definitely not doing Q8 so anything besides that.

Thanks!

booblefoop

robman60 wrote: »

Hi guys,

I'm going to have to cram desperately tonight, as I've neglected this subject completely.

If you were to advise me to study four experiments, what would they be? What other sections should I definitely cover in the limited time I have left? I'm definitely not doing Q8 so anything besides that.

Thanks!

Definitely learn your titration method/calculations as they'll be pretty much the same no matter what the question, and one comes up every year.