[Booyah]

(Original post by This Honest)
Ok but with another paper, the arrows were meant to go up (formation) but when i did the gravity thingy, it went down :/

Look at the definition what are you forming? If your forming NaCl then the elements would point towards the compound. as Elements------> Product

[neom]

(Original post by This Honest)
Ok but with another paper, the arrows were meant to go up (formation) but when i did the gravity thingy, it went down :/

I've tried it out multiple times and it works everytime..
What paper was it? I'll try it out on that one

[This Honest]

(Original post by neom)
I've tried it out multiple times and it works everytime..
What paper was it? I'll try it out on that one

May 10

[This Honest]

(Original post by Booyah)
Look at the definition what are you forming? If your forming NaCl then the elements would point towards the compound. as Elements------> Product

I understand that but it's the gravity issue that I'm puzzled about.

[Booyah]

(Original post by This Honest)
I understand that but it's the gravity issue that I'm puzzled about.

I would ignore that part, otherwise his method seems good Just remember the definitions and what the end product is.

[TenaciousMonkey]

(Original post by This Honest)
I understand that but it's the gravity issue that I'm puzzled about.

The gravity thing is just that the paper sweeps downwards so the arrow points down, that's all.

[neom]

(Original post by This Honest)
May 10

That's the question where I first tried out this method and the arrows all went up.
And I just tried it out again, and the same thing happened.
If it's confusing you maybe you should ignore it.
Sorry..

[This Honest]

(Original post by neom)
That's the question where I first tried out this method and the arrows all went up.
And I just tried it out again, and the same thing happened.
If it's confusing you maybe you should ignore it.
Sorry..

ahhhh nvm dude
Thanks for trying

[James A]

(Original post by This Honest)
ahhhh nvm dude
Thanks for trying

yo dude what did you get for this the first time?

[ummm]

(Original post by This Honest)
Much more confident than last time
Things are so much easier when you understand it rather than memorise it
Jan 12 was a toughie...hope it's slightly easier next week.

Are you ready for it?



I hate hess law, I just hope it's a easy one.
Could you explain your teacher's tip a bit more...don't really understand

Ahh, I didn't take it in January, so this'll be my first time! But since doing unit 2, all the understanding of the content has just clicked into place. Before I had just memorised it so didn't really understand it so found it really difficult to apply to questions! I did January 2012 the other day... it was a pretty hard one! I just hope I don't freak out when I get to a question that confuses me.

Why do they always have to twist everything!? haha! My teachers say that Edexcel is by far the hardest board for the exams... I think we're quite lucky with our assessed practicals compared to ISAs on AQA though!

Ahh, I'm going to be so nervous for this exam! Have biology on Monday first though. Do you do biology?

By the way, for Hess' law, I've found that unless you're using enthalpy changes of formation, the arrows will always point down. If you think about it, it's really straight forward! If you're using enthalpy change of combustion, then obviously the arrows are going to be pointing down, as both the reactants and products produce H20 and C02 when they burn. And if you're doing enthalpy changes of formation, then you just list all the elements in their standard states at the bottom, and because both the reactants and products come from these elements, the arrows point upwards from the elements!

And then it's just simple vectors (well that's always how I think of it).

(I REALLY struggled with Hess' Law at one point!)

[This Honest]

(Original post by James A)
yo dude what did you get for this the first time?

94 last jan, then 93 last june.
Didn't sit jan 12.

What did you get?
Are you sitting the exam?

[This Honest]

(Original post by ummm)
Ahh, I didn't take it in January, so this'll be my first time! But since doing unit 2, all the understanding of the content has just clicked into place. Before I had just memorised it so didn't really understand it so found it really difficult to apply to questions! I did January 2012 the other day... it was a pretty hard one! I just hope I don't freak out when I get to a question that confuses me.

Why do they always have to twist everything!? haha! My teachers say that Edexcel is by far the hardest board for the exams... I think we're quite lucky with our assessed practicals compared to ISAs on AQA though!

Ahh, I'm going to be so nervous for this exam! Have biology on Monday first though. Do you do biology?

By the way, for Hess' law, I've found that unless you're using enthalpy changes of formation, the arrows will always point down. If you think about it, it's really straight forward! If you're using enthalpy change of combustion, then obviously the arrows are going to be pointing down, as both the reactants and products produce H20 and C02 when they burn. And if you're doing enthalpy changes of formation, then you just list all the elements in their standard states at the bottom, and because both the reactants and products come from these elements, the arrows point upwards from the elements!

And then it's just simple vectors (well that's always how I think of it).

(I REALLY struggled with Hess' Law at one point!)

Ahh ok
I think edexcel is easier than aqa tbh

I do biology I'm not resitting unit 1, but i'm doin 2,4, and 5 this summer.

thanks for that, I understand it when it talks about combustion or formation so that's good.

EUGH! I hate vectors...you're reminding me of C4

[ummm]

(Original post by This Honest)
Ahh ok
I think edexcel is easier than aqa tbh

I do biology I'm not resitting unit 1, but i'm doin 2,4, and 5 this summer.

thanks for that, I understand it when it talks about combustion or formation so that's good.

EUGH! I hate vectors...you're reminding me of C4

Arghh, so much biology, haha! I'm doing unit 2 too... still need to do loads of papers for it though.

And hahah! I have no experience of C4 vectors, only nice GCSE ones.

Good luck!

[James A]

(Original post by This Honest)
94 last jan, then 93 last june.
Didn't sit jan 12.

What did you get?
Are you sitting the exam?

I only sat it in last June and got 100.

That was the only chemistry paper where i got triple digits lol

[16ARTER]

Hey guys,

I just did the january 2012 paper, and came across Q25 b which seemed confusing as the answer is 'the structural formula of any polyhalogenated ethane derivative' Can anyone explain what it is meant by polyhalogenated ethane derivative??

Thanks,

[TenaciousMonkey]

(Original post by 16ARTER)
Hey guys,

I just did the january 2012 paper, and came across Q25 b which seemed confusing as the answer is 'the structural formula of any polyhalogenated ethane derivative' Can anyone explain what it is meant by polyhalogenated ethane derivative??

Thanks,

It just means CH3CH2Cl2, CH3CHCl3, etc.

[S1L3NTPR3Y]

Has anyone got the mark scheme for Jan 2012 Unit 1?

And here is a link for the paper for practice: http://www.scribd-downloader.com/dow...-2012-88262768

[James A]

(Original post by 16ARTER)
Hey guys,

I just did the january 2012 paper, and came across Q25 b which seemed confusing as the answer is 'the structural formula of any polyhalogenated ethane derivative' Can anyone explain what it is meant by polyhalogenated ethane derivative??

Thanks,

it means more than one halogen group is attatched to that ethane molecule.

for example CH3CH(Cl)(Br)

[sabre2th1]

(Original post by S1L3NTPR3Y)
Has anyone got the mark scheme for Jan 2012 Unit 1?

And here is a link for the paper for practice: http://www.scribd-downloader.com/dow...-2012-88262768

There ya go

[Wooden]

Any predicitions what is likely to come up?

any must knows? etc

Ofcourse we should all know that they will put a question probably dedicated for a few calculations (moles..)