nav[aria-label="Primary Navigation"] { padding: 0; & ul { list-style: none; width: 100%; display: flex; flex-direction: row; justify-content: start; align-items: start; gap: 30px; padding: 0; & li { margin: 0; } & ul li { list-style: none; } } }

Child Item

Leaving Certificate Chemistry [All Levels] Before and After Discussion

plmko

A good few days to go yet but Chemistry is on our horizons people!

-Predictions for the experiment questions?

-Will it be a tough paper?

-What should we look over?

Find more posts tagged with

leaving

cert

chemistry

2014

certificate

Quick Links

Comments

MacBizzle

jellytots95 wrote: »

Is it not colourless to faint permanent pink?

That's what I thought.

What book is it plmko?

jellytots95

plmko wrote: »

Could someone please clarify for me what is the colour change at the endpoint of the KMnO4 and ammonium iron II sulfate titration? My book is very confusing about it.

First they say it's faint permanent pink to permanent pink (as in it got darker which makes sense as KMnO4 is a strong purple colour) and then they say it went faint permanent pink to faint pink.

How did it suddenly change from permanent to non-permanent?

Is it not colourless to faint permanent pink?

plmko

Could someone please clarify for me what is the colour change at the endpoint of the KMnO4 and ammonium iron II sulfate titration? My book is very confusing about it.

First they say it's faint permanent pink to permanent pink (as in it got darker which makes sense as KMnO4 is a strong purple colour) and then they say it went faint permanent pink to faint pink.

How did it suddenly change from permanent to non-permanent?

TooMuchStudy

MacBizzle wrote: »

Don't they come up every year in some shape or form?

I have no idea, done no exam paper work and don't have my exam papers with me ðŸ˜

craig9614

I'm doing ordinary level and was wondering what to study over the week end .. Any predictions let me know, cheers

MacBizzle

TooMuchStudy wrote: »

What are the chances of a gas question coming up this year?

Don't they come up every year in some shape or form?

TooMuchStudy

What are the chances of a gas question coming up this year?

MacBizzle

wafture wrote: »

Hach test kit?

You might have done the colorimeter, it's the free chlorine experiment in the water chapter.

wafture

Hach test kit?

MacBizzle

JDOC1996 wrote: »

Predictions ?

What can we really predict? Chemistry doesn't change much, all I've heard is soap being tipped, and the Hach test kit.

JDOC1996

Predictions ?

MacBizzle

Ompala wrote: »

Off the top of my head, isn't potassium iodide used in the winkler method for determining dissolved oxygen?

Yep, alkaline KI and manganese sulfate I think

Ompala

MacBizzle wrote: »

Think we must have skipped an experiment so, or else I just wasn't listening... :rolleyes:

Off the top of my head, isn't potassium iodide used in the winkler method for determining dissolved oxygen?

MacBizzle

Ompala wrote: »

Nope, Potassium Iodate is KI03 while potassium iodide is KI.
-ate is used in the naming of things that contain oxygen e.g iron sulfate FeSO4

Think we must have skipped an experiment so, or else I just wasn't listening... :rolleyes:

Ompala

MacBizzle wrote: »

Are potassium iodate and potassium iodide the same thing?

Nope, Potassium Iodate is KI03 while potassium iodide is KI.
-ate is used in the naming of things that contain oxygen e.g iron sulfate FeSO4

MacBizzle

Are potassium iodate and potassium iodide the same thing?

EoghanIRL

accountname wrote: »

Formula is; heat= m * c * (t2-t1)
where m = mass in kg
c= specific heat capacity of solution given in the question
and t2-t1 is the difference in the temperatures
Just sub in all them and you'll get your heat in kJ/mol

'Tis a dirty calculation but as you said, it came up last year so I wouldn't worry too much about it :P

It was on pre for heats of reaction question . If you do physics then the mc delta t thing is so easy:P

accountname

plmko wrote: »

Thanks! And how do you do the calculations?

Formula is; heat= m * c * (t2-t1)
where m = mass in kg
c= specific heat capacity of solution given in the question
and t2-t1 is the difference in the temperatures
Just sub in all them and you'll get your heat in kJ/mol

'Tis a dirty calculation but as you said, it came up last year so I wouldn't worry too much about it :P

plmko

accountname wrote: »

For the HCl and NaOH, just know the formula for it and the units you have to convert the figures to. If they ask it in Section B I'd only see them asking a calculation for it

Thanks! And how do you do the calculations?

accountname

plmko wrote: »

What's the timing for Chemistry? Twenty mins per question or..?

22 mins per question. You'll probably find you get them done quicker than this, so you should have plenty of time for an extra question

For the HCl and NaOH, just know the formula for it and the units you have to convert the figures to. If they ask it in Section B I'd only see them asking a calculation for it

MacBizzle

plmko wrote: »

What's the timing for Chemistry? Twenty mins per question or..?

22 and a half minutes per question if you want to get 8 done.

20 per question and you'll get 9 done, which I'll be doing because I'm bound to mess up one question

plmko

Could anyone explain the heat of neutralisation experiment with HCl and NaOH please? I know it came up last year but just incase it appears in Section B.

What's the timing for Chemistry? Twenty mins per question or..?

Soapndglory

WoolyAbyss wrote: »

Do we need to know the diagrams for the organic experiments or do they always give them?
The ethanal and ethanoic acid ones would be horrible to draw.

Yes you have to be able to draw all the apparatus cus they can ask on it and it'll be worth a fair few marks! My teacher has drilled us to be able to draw them in under 4 minutes!!

WoolyAbyss

Do we need to know the diagrams for the organic experiments or do they always give them?
The ethanal and ethanoic acid ones would be horrible to draw.

accountname

MacBizzle wrote: »

Anyone else want the DEB paper?

If you don't mind? :rolleyes:

marno21

My apologies for the negativity

I won't say what I was going to say next

Easy experiment questions, 3 atomic theory, 2 fuels + heats of reaction + 2 water anyone?

little sis...

Why does everyone think it will all go wrong THIS year?
Who cares if another person is setting it? It's hardly going to have some dramatically different layout and question types.
Why don't we all get excited about the fact it may well be a lovely paper

MacBizzle

marno21 wrote: »

World Cup 2 - 0 Chemistry study

What I meant abotu the biology is the biology paper was different to all the other years this year. None of the usual topics and strong emphasis on lesser stuff.

Imagine a paper this year with no atomic theory as q5 etc. (sorry for scaring some of ye)

Please stop.

marno21

World Cup 2 - 0 Chemistry study

What I meant abotu the biology is the biology paper was different to all the other years this year. None of the usual topics and strong emphasis on lesser stuff.

Imagine a paper this year with no atomic theory as q5 etc.

(sorry for scaring some of ye)

Murky013

little sis... wrote: »

Ethylene?

Sorry I meant ethyne. Feckin' autocorrect. :P