[This Honest]

Chemistry Unit 1- The Core Principles of Chemistry


Hey guys,

I haven't seen a thread for this so I thought I'd make one
Currently 8 weeks and 1 day till the exam, not that I'm counting

So post your questions/queries/issues with unit 1 chem on this thread and hopefully, other members of TSR including myself can try and help out.

I'm currently in A2 but my teacher kinda forced me to resit it as a safety net to get the A grade. I'm a little bit rusty on unit 1 since I ain't looked at it since last year

Let the battle discussion begin...


Update: The exam begins in a couple of hours, please refrain from talking about the exam in this thread or other threads (which are likely to pop up!). Exam discussion will be allowed from 04:30 AM Wednesday.

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[This Honest]

Bump

[kitriviolet]

i did unit 1 in jan and got 120/120 in UMS. so id say yeah..there are a few things you must rmb while going into the room?

-factors affecting first ionization energy & reasons for trends across periods/down groups
-factors affecting extent of covalency in lattices
-factors affecting strength of metallic bond & trends across periods
-factors affecting lattice energy
-whats happening with successive ionization energies
-principle of mass spectrometer
-difference between risk & hazard, and also between precision & accuracy
-what is happening in born-haber cycles
-all the reactions of organic compounds

and of course, dont forget to swallow down how the mechanisms are drawn..and definitely the hess cycles. hess cycles are bound to come up..and mechanisms 80% of the time.

good luck im struggling with A2 as well!

[d_94]

Aghh. Hate this exam :/ Damnn

[This Honest]

Thank you kitriviolet and well done on that amazing ums. I was stalking the unit 1 jan 12 thread and quite a lot of people got over 100UMS.
I haven't done the jan 12 exam yet, will do this week but was it that hard or that easy?

D_94, I know, I dislike this unit a lot but i've been doing lots of questions and I'm quite prepared.

Anything you need help in, just ask

I'm on my itouch so I can quote you guys

[kitriviolet]

youre welcome and thanks umm i actually thought id get a B or a C when i left the exam room, so yep, my results left me quite surprised.

i love AS most our local syllabus has covered most of it, whereas i have to self-teach A2. at least my chemistry teacher is willing to help, because the old A level in our area covers most of that too

(Original post by This Honest)
Thank you kitriviolet and well done on that amazing ums. I was stalking the unit 1 jan 12 thread and quite a lot of people got over 100UMS.
I haven't done the jan 12 exam yet, will do this week but was it that hard or that easy?

D_94, I know, I dislike this unit a lot but i've been doing lots of questions and I'm quite prepared.

Anything you need help in, just ask

I'm on my itouch so I can quote you guys

[ummm]

Does anyone know how many marks you can usually drop and still get around 110-120 UMS in this exam? I've been doing some past papers, and have been dropping about 5 marks in them... No idea what that would equate to in terms of UMS though!

[kitriviolet]

ive been trying to find out too..it varies every time, but rest assured ive lost more than 5 marks on my past papers and still got 120/120 for units 1 and 2 good luck!

(Original post by ummm)
Does anyone know how many marks you can usually drop and still get around 110-120 UMS in this exam? I've been doing some past papers, and have been dropping about 5 marks in them... No idea what that would equate to in terms of UMS though!

[ummm]

(Original post by kitriviolet)
ive been trying to find out too..it varies every time, but rest assured ive lost more than 5 marks on my past papers and still got 120/120 for units 1 and 2 good luck!

Thanks. Your results are actually so amazing! I'm so jelly! I've dedicated a lot of time to chemistry, and found unit 2 hard when I was learning it, but it's kind of clicked into place now. The mechanisms and stuff in unit 2 makes the content in unit 1 seem so much easier! Chemistry is probably my hardest subject!

How much harder is A2 compared to AS?

[kitriviolet]

hahahahah no i got lucky i guess you can try out more exercises so you get to apply your knowledge instead of cramming them into your brain? it helps a lot to mull over the content when you have nth to do, like when youre eating or waiting for a bus..:P

A2 is freaky, or maybe its just the fact that its been cut from our local syllabus and we dont get to learn it. but with hard work, its not impossible! i find it easier and easier as time goes by..:P

(Original post by ummm)
Thanks. Your results are actually so amazing! I'm so jelly! I've dedicated a lot of time to chemistry, and found unit 2 hard when I was learning it, but it's kind of clicked into place now. The mechanisms and stuff in unit 2 makes the content in unit 1 seem so much easier! Chemistry is probably my hardest subject!

How much harder is A2 compared to AS?

[Babyblue]

ill be re-sitting this. havent done anything for it yet. what practice questions should i do?

i got 92 ums last jan. hoping for an A.

Should i stick to pastpapers? and also, what textbook/revision guide are you using?

[Ataraxian-Walker]

-factors affecting extent of covalency in lattices
-factors affecting strength of metallic bond & trends across periods
-factors affecting lattice energy
-whats happening with successive ionization energies

Can someone please help me with these?

[ummm]

(Original post by Ataraxian-Walker)
-factors affecting extent of covalency in lattices
-factors affecting strength of metallic bond & trends across periods
-factors affecting lattice energy
-whats happening with successive ionization energies

Can someone please help me with these?

Hey, I don't have the time atm to write everything out, but I just thought I'd say that I used to struggle with remembering all of this sort of stuff, and spent ages trying to memorise all the different trends, but honestly it's SO much easier to just understand it, and work it out when you're asked it! It's always either to do with: electron shielding, distance between the outer electron and nucleus, charge density, delocalised electrons, increasing/decreasing nuclear charge.

I suggest you go through your notes/textbook/revision guide and really understand why the patterns are what they are. Then it becomes really easy!

[This Honest]

(Original post by Ataraxian-Walker)
-factors affecting extent of covalency in lattices
charge density, larger the charge density, the poorer the match between the experimental and theoretical value will be, larger the radius of the anion, the more the polarised it will become.
-factors affecting strength of metallic bond & trends across periods
ionic charge can affect metallic bond higher the charge, more electrons supplied to the cation
-factors affecting lattice energy
Ionic Charge and Ionic Radius - the smaller the radius the greater the lattic energy
-whats happening with successive ionization energies
one electron is being removed one at a time, starting with the outermost electron, then going in. If there's a big jump between 2 ionisation energy, then a new shell has started to lose its electrons.

For example, if the first big jump is between 3rd and 4th IE, then the element would be in group 3


Can someone please help me with these?

Hope I helped

[Ataraxian-Walker]

(Original post by This Honest)
Hope I helped

Thank you so much (: x

[This Honest]

(Original post by Ataraxian-Walker)
Thank you so much (: x

No problem

[Babyblue]

can somebody explain me the hess cycle?

[senz72]

This is the test I'm going to flop so badly along with unit 2. I don't even get 50% in the multiple choice!

[This Honest]

(Original post by Babyblue)
can somebody explain me the hess cycle?

Gosh! I hate that so much, unfortunately, it WILL come up, either in the MCQ or section B, most likely the latter.
I went to my teacher to explain the hess cycle in the jan 12 paper

(Original post by senz72)
This is the test I'm going to flop so badly along with unit 2. I don't even get 50% in the multiple choice!

Looking at the examiner reports, the average score of MCQ tends to be around 13-15. Unit 1 MCQ is pretty robust for some reason, unit 2, 4 and 5 are much easier.