[cuckoo99]

indeed i had problems with it to begin with but my teacher went over it in some revision sessions and now im ok with it

[Hdizzle]

*sigh*
hello everyone
just had a look at a past paper. let's just say if i sat it now i would fail..miserably.
Is anyone using the small chem 2 aqa book, if so is it of any use?
haven't got any notes other than class notes so thought I should get cracking with
getting some material seeing the exam is in exactly 2 months time in 3/4 days D:

Got my written ISA paper on wednesday ><

[Doctor.]

(Original post by Hdizzle)
*sigh*
hello everyone
just had a look at a past paper. let's just say if i sat it now i would fail..miserably.
Is anyone using the small chem 2 aqa book, if so is it of any use?
haven't got any notes other than class notes so thought I should get cracking with
getting some material seeing the exam is in exactly 2 months time in 3/4 days D:

Got my written ISA paper on wednesday ><

The tiny blue collins book? It's a great book for going into extra detail! Although the Nelson Thorns book is pretty good too. It's easier to understand, after going over the chapter with NT only then would I use the Collins book!

Whatever suits your revision though

[Tullia]

(Original post by Mocking_bird)
Just the different sets of reactions like halide ions and sulphuric acid or test for halide ions and the different equations/ppts/colour changes.

It will just take some revision but as of now its just not sticking.

I'm taking it you've just done the theory part of Halogens and not been through the practicals first-hand yet? Conceptually it isn't difficult though, so as you say, just getting into it and practicing will hammer it home.

I've got 2 Chemistry teachers now, with my first experience of my new teacher coming on Wednesday. Not really impressed with a teacher more used to teaching Forensic Science being thrown at me so far into the year, but we'll see.

[Mocking_bird]

(Original post by Tullia)
I'm taking it you've just done the theory part of Halogens and not been through the practicals first-hand yet? Conceptually it isn't difficult though, so as you say, just getting into it and practicing will hammer it home.

I've got 2 Chemistry teachers now, with my first experience of my new teacher coming on Wednesday. Not really impressed with a teacher more used to teaching Forensic Science being thrown at me so far into the year, but we'll see.

We've seen the practicals too but they didnt really help me much either .

Eesh I wouldnt like having two teachers I need things to be taught in one style for each subject otherwise I would be so confused.

[3.14Pie]

(Original post by Hdizzle)
*sigh*
hello everyone
just had a look at a past paper. let's just say if i sat it now i would fail..miserably.
Is anyone using the small chem 2 aqa book, if so is it of any use?
haven't got any notes other than class notes so thought I should get cracking with
getting some material seeing the exam is in exactly 2 months time in 3/4 days D:

Got my written ISA paper on wednesday ><

I have mine on wednesday as well good luck! I dont want to fail it but apparently its harder to get a good grade in for anyone because of so many schools cheating

[Doctor.]

(Original post by 3.14Pie)
I have mine on wednesday as well good luck! I dont want to fail it but apparently its harder to get a good grade in for anyone because of so many schools cheating

So many schools do it, too few 'good' teachers...Actually they're rather awful teachers since they full well know it happens yet they wont help their students. Annoys me greatly

[alt31]

3rd time sitting unit 2!! (along with 1,4 and 5 )
hopefully this gets better
but i'd say it seems like a doss compared to unit 4!
hahahaaa
most important thing to grasp is mechanisms, cause they also really help with A2 year aswell
good luck everyone, tsr threads like this really help for revision though!

[AishaTara]

hey
just wondering if someone could help me understand this:

chromium metal reacts with chlorine to make chromium (III) ions and chloride ions? write the full equation, and show half equations too.


any ideas? As I get two metals on one side, and 5 electons on the other so dont know how to balance that

[Mocking_bird]

(Original post by AishaTara)
hey
just wondering if someone could help me understand this:

chromium metal reacts with chlorine to make chromium (III) ions and chloride ions? write the full equation, and show half equations too.


any ideas? As I get two metals on one side, and 5 electons on the other so dont know how to balance that

The equation as you are told is Cr + Cl2 -> Cr3+ + Cl-

Start with the 2 half equations:
Cr -> Cr3+ + 3e-
Cl2 + 2e- -> 2Cl-

You need to times the top equation by 2 and the bottom equation by 3 so you can cancel out the electrons.

2Cr -> 2Cr3+ + 6e-
3Cl2 + 6e- -> 6Cl-

Combine the 2:
2Cr + 3Cl2 -> 2Cr3+ + 6Cl


I think this is right, but feel free to correct if it isnt, anybody.

[Doctor.]

(Original post by alt31)
3rd time sitting unit 2!! (along with 1,4 and 5 )
hopefully this gets better
but i'd say it seems like a doss compared to unit 4!
hahahaaa
most important thing to grasp is mechanisms, cause they also really help with A2 year aswell
good luck everyone, tsr threads like this really help for revision though!

Hey! I did 1, 2 and 5 in January so believe me it is possible to do it . It was my 3rd attempt at Unit 2 as well .

If you need any help in CHEM4, let me know I am working on that right now!
Good luck with yor studies

[Doctor.]

(Original post by Mocking_bird)
The equation as you are told is Cr + Cl2 -> Cr3+ + Cl-

Start with the 2 half equations:
Cr -> Cr3+ + 3e-
Cl2 + 2e- -> 2Cl-

You need to times the top equation by 2 and the bottom equation by 3 so you can cancel out the electrons.

2Cr -> 2Cr3+ + 6e-
3Cl2 + 6e- -> 6Cl-

Combine the 2:
2Cr + 3Cl2 -> 2Cr3+ + 6Cl

I think this is right, but feel free to correct if it isnt, anybody.

It's right well done +1 for good explation!!

On second though....I am unable to +rep . Sorrrrry

[alt31]

(Original post by Doctor.)
Hey! I did 1, 2 and 5 in January so believe me it is possible to do it . It was my 3rd attempt at Unit 2 as well .

If you need any help in CHEM4, let me know I am working on that right now!
Good luck with yor studies

good to hear!
yes lets be chem4 revision buddies! failed horrendously last time

what do you need in chem? and what do you want to do at uni?

[Doctor.]

(Original post by alt31)
good to hear!
yes lets be chem4 revision buddies! failed horrendously last time

what do you need in chem? and what do you want to do at uni?

I need an A, which Is actually really achievable now! And Pharmacy at LJMU!

CHEM4 is really bugging me though, everything from amino, Amines and polymers...there's quite a bit of memory on kevlar etc which is so damn hard! Really do need a revision buddy so...you're mine lol. Oh an yeah, if you need anything else In Chem just ask me! (or else....)


PS i have made a topic thing in the chemistry exams section of the foruns for CHEM4, you best be there

hehe, you'll do fine

[alt31]

(Original post by Doctor.)
I need an A, which Is actually really achievable now! And Pharmacy at LJMU!

CHEM4 is really bugging me though, everything from amino, Amines and polymers...there's quite a bit of memory on kevlar etc which is so damn hard! Really do need a revision buddy so...you're mine lol. Oh an yeah, if you need anything else In Chem just ask me! (or else....)


PS i have made a topic thing in the chemistry exams section of the foruns for CHEM4, you best be there

hehe, you'll do fine

same, need an A. we can do it!
uhh its horrible, terylene haunts my nightmares :P
i'll be there don't worry! will go find it now and subscribe, can't miss out on a spot of revision.
how did you do in your jan chem exams?

[Hughsie]

Im sitting Unit 2 in May and RESITTING Unit 1 (cause I love it so much..), what do people mean by Mechanisms?? Is it the extraction processes or what? Bare in mind we havnt completed the course..

[MedicalMayhem]

Hi, I've got a question concerning redox half equations and wondered if someone could help.

S2O3^2- -> S4O6^2-

I've having trouble understanding this example. I understand that you add a '2' to the left, to balance out the number of Sulphurs. What happens to the charge then? Does the 2- become 4-? And would it be 4S - 12 (6 O's) = -4? Or would it be 2S - 6 = -4. I'm confused to what the 2 would actually do :/

[AishaTara]

(Original post by Mocking_bird)
The equation as you are told is Cr + Cl2 -> Cr3+ + Cl-

Start with the 2 half equations:
Cr -> Cr3+ + 3e-
Cl2 + 2e- -> 2Cl-

You need to times the top equation by 2 and the bottom equation by 3 so you can cancel out the electrons.

2Cr -> 2Cr3+ + 6e-
3Cl2 + 6e- -> 6Cl-

Combine the 2:
2Cr + 3Cl2 -> 2Cr3+ + 6Cl


I think this is right, but feel free to correct if it isnt, anybody.

hey this is right thank you

[Doctor.]

(Original post by alt31)
same, need an A. we can do it!
uhh its horrible, terylene haunts my nightmares :P
i'll be there don't worry! will go find it now and subscribe, can't miss out on a spot of revision.
how did you do in your jan chem exams?

I didn't do too bad, chemistry was the best for me. Even though CHEM1 exam was an absolute nightmare .

Ergh Terylene ...I have that stuff with a passion..


lol you'll find this weird...I am scared of doing CHEM4 papers because I keep thinking I will run out or I will get such a bad score I will just end up jumping off my roof . The latter will probably happen though . I fear CHEM4 papers .

Need to start soon though

[Doctor.]

(Original post by MedicalMayhem)
Hi, I've got a question concerning redox half equations and wondered if someone could help.

S2O3^2- -> S4O6^2-

I've having trouble understanding this example. I understand that you add a '2' to the left, to balance out the number of Sulphurs. What happens to the charge then? Does the 2- become 4-? And would it be 4S - 12 (6 O's) = -4? Or would it be 2S - 6 = -4. I'm confused to what the 2 would actually do :/

Woah this is a little beyond AS for starters, more like CHEM5, where is this quesion from?

Not got any paper next to me atm...will check in a hour though!