Jump to content

IB Chemistry HL Revision advice?! (may2016)

Recommended Posts

Hi everybody :) 

 

I'm currently in IB2 my exams are exactly two months from today and i need to start revision but when it comes to chemistry i'm completely lost! My aim for the final is to hopefully achieve a 5 (a 6 would be great but honestly i'd be equally happy with a 5 it's all i need for uni) so my question is does anyone have advice on how to achieve this? Do i take notes? read from the book? past paper questions are a must of course. And for those of you who have taken IB before how did you all revise? and did it help you achieve the grade you wanted? 

 

any and all advice is appreciated :)

 

Share this post


Link to post
Share on other sites

I didn't take HL, just SL, and in the old syllabus (or I think, at least, that it changed since then). The green/blue Geoff Neuss guide (which probably changed its cover in the meantime) was enough of a revision for me. If I didn't exactly understand some concept, I'd go for help to the Pearson Baccalaureate book (I loved the pearson baccalaureate books, they were so colourful and full of clear graphs and explanations). Plus literally all of the past papers I could get my hands on, timed. 

Share this post


Link to post
Share on other sites
On 3/2/2016 at 5:33 AM, Hannah7245 said:

I'm currently in IB2 my exams are exactly two months from today and i need to start revision but when it comes to chemistry i'm completely lost! My aim for the final is to hopefully achieve a 5 (a 6 would be great but honestly i'd be equally happy with a 5 it's all i need for uni) so my question is does anyone have advice on how to achieve this? Do i take notes? read from the book? past paper questions are a must of course. And for those of you who have taken IB before how did you all revise? and did it help you achieve the grade you wanted? 

I assume you are not quite getting a solid 5, so I'll propose a plan to help you get a 6 or maybe a 7. There are two aspects: practicing techniques, and understanding relationships (and if not completely understanding, some level of pattern recognition also works). This should be accompanied by going over the guide (syllabus) in detail. I used a slightly different plan because I wasn't getting below a 5 but I still focused on these two aspects.

By techniques I mean the really specific, often equation-oriented questions they will ask you. For example, "Balance this redox reaction." If you do 50 problems from easy to hard just balancing redox in both acidic and basic conditions, you will have a greater chance of getting these problems as long as you practice once more right before final exams. If you aren't given these worksheets try find some online. 
Topics you should study by this technique includes:

  • solve for any variable in any and all equations in Table 1 of Data Booklet
  • unit conversions (eg mol/L, mol/cm^3, mol/dm^3, kJ and J, Celsius and Kelvin, using correct gas constant)
  • enthalpy (by bond dissociation/formation, by enthalpy of formation, by definition of free energy)
  • heat transfer
  • rates (Arrhenius equation, first order/second order integrated rate laws solving for k, and Temperature)
  • balance redox reactions in acidic or basic conditions
  • free energy and equilibrium, free energy and E_cell (cell potential)
  • equilibrium with initial conditions and/or with equilibrium constant
  • applying Le Châtelier's principle
  • pH of buffer solutions and pH at equivalence point of a weak acid-strong base or weak base-strong acid titration
  • Energy difference and colour in d-orbital splitting
  • drawing organic chemistry mechanisms (consult with past papers!)
  • drawing the enantiomer
  • naming compounds / identify functional groups (don't spend too much time, know up to 6 carbons on the main chain, know nitrile, ester, amide and other basic nomenclature is sufficient)
  • Using mass spec, IR, NMR to identify compound
  • formal charge / drawing Lewis dot diagrams
  • identifying hybridization / number of sigma and pi bonds present

For understanding, you don't need every specific detail to get a 6. It's more important to know overarching themes and be able to predict some of the specific details even if you can't memorize them. It's hard to list all the relationships possible, but here are some more subtle ones perhaps you thought little of.

  • Bonding energy is negative. The more negative the bonding energy is, the stronger the bond. So when bond is broken, energy of the molecule increases (closer to 0) because we have less bonding energy. More (less negative) energy also means it's less stable, as compared to really negative energies which are more stable.
  • By conservation of charge, for every reaction involving an acid, there is a base; for every species oxidized, there is a species (not necessarily distinct) that is reduced. Parallelism can be drawn without confusing the two types of reactions
  • Coulomb's law state that force between two atoms increase with product of the charge and decrease with the distance in between. You don't need to know how to use Coulomb's law but the concept is important. Stronger the attractive force, more negative energy (more stable). Stronger the repulsive force, more positive energy (less stable). For example iodide ion is so much bigger than fluoride ion, such that the negative charge is more spread out, lowering the positive energy and hence iodide ion is so much more stable than fluoride ion. Also, iodide is a much weaker base than fluoride because of its stability. 

These are insights you should eventually work towards. For starters, it could be just understanding a specific concept without resorting to memorization. Eg identifying positive and negative ends, as well as electron flow, of voltaic and electrolytic cells. It wouldn't help you very much to just memorize the directions. In voltaic cells, oxidation provides electrons so that's the negative end, reduction used up electrons, so reduction is the positive end. What's different in electrolysis is that there is no accumulation of electrons because each reaction needs energy and is non-spontaneous, such that electrons move away from the anodes faster, leaving all the cations behind. In voltaic cell, flow of electron in spontaneous direction, or negative to positive direction. In electrolysis, flow of electron in non-spontaneous direction, or positive to negative direction. 

You will going to feel frustrated initially when using this method because it's hard to understand conceptually. But spending those extra efforts making the connects will pay off in the long run as opposed to plain memorization. 

Videos are certainly helpful. But it's erroneous to think that every minute of video covers equal valuable content because there is really no point in understanding the minute details when you do not understand the large picture, the overarching themes. Spend more time watching videos or read explanations about the core concepts (such as in the knowledge and understanding sections of the guide/syllabus) instead of aiming to watch an entire playlist once. It's easier to finish a playlist without having really absorbed the knowledge, instead the best bet is to struggle through understanding the key concept, which will automatically make understanding the details so much easier. You can watch however number of videos or read as many chapters you like, but the ultimate goal is to click or conceptually understand. Once you do, it's more likely you will retain the knowledge.

Edited by kw0573
  • Like 9

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.