Official OCR- AS Chemistry F321 January 2013 (revision, questions)

Hey
I'm doing as chem and I'm finding it hard to memorise some if the things. Any advice?


This was posted from The Student Room's iPhone/iPad App

yes sure

REvising Chemistry :

For Chemistry, there is no way you can score well in examinations just by memorising the facts and definitions in your Chemistry Textbooks or Chemistry Notes.

The way to learn effectively is to make sure you understand the essential chemistry concepts. For revision, it is recommneded that you tackle it in a topical basis first, before coming back to do a summary of how the different topics are interlinked together (if you do not realised there’s interlinking in the different topics, then this be a RED ALERT for you).

Before beginning to revise a topic:
•Have a brief ideas of the learning objectives of the topics – what are you required to know?
•Take a look at section headings and sub-headings to get an overall idea of what is covered
•Think about how much you already know about this topic – just some points and keywords

During the revision of the topic:
•Underline of highlight important points – you can also write them out in point forms
•Lists out important facts, diagrams or definitions – they are usually tested
•Understand all the different terms – you can use the annex @ back of textbook or Up Your Chemistry Grades Now! (yes, i have compiled a comprehensive list of chemical definitions that all O Levels Chemistry students must know)
•Attempt the questions in your Chemistry Textbooks, Workbooks, Ten Years Series or questions in this blogsite
•Identify those points that you are not sure and confused about – approach your teacher or tutor to find out the answer! Do NOT ignore any confusions because they will become MISCONCEPTIONS in your Chemistry Exams.
•Alternatively, you can write in to me at [email protected]. Understanding of chemistry concepts is the key to effective learning and getting you the grades you desire

After revision of the topic:
•Look at the summary or concept link @ the end of your textbook – you should be confident now that you have covered those angles
•Make your own summary of the topic by various methods you are comfortable with: MindMaps, Tables, Flowcharts, Concept Maps, Point Forms, etc…Rmbr – use the method you most comfortable now. No time now for you to try something new..thou you heard it is useful
•Try out more questions in ten years series, this humble chemistry blogsite (yeah..lots of exam-based questions) and your textbooks.

With the proper “closure” of the topic, celebrate with little success by doing something you like (not too much time taken thou) such as get a cola drink, get an ice-cream, read some magazines or papers, half an hour of video games or FACEBOOK/MSN etc. You need to learn how to enjoy and reward yourself in order to be motivated to continue on. [if your parents disallow that, you can refer them to this humble website].

But you cannot play me out – i.e. don’t say this website encourage you to play 5 hrs of games/FACBOOK.MSN after only revising 1 topic. You will kill get me into trouble…haha =)

Once you have revised at least once for each chapter that is tested in your Mid-Year Examinations – it is time for you to close all notes and just look @ your content page. We need to do an overall summary of it. Based on your sub-headings – i want you to close ur eyes and try to recall as many small points / facts on each sub-headings. You would realise that many of the terms used are actually re-occuring in our topics.

I hope you will find the above Examination Strategies / Tips on Revising for Chemistry Examinations (Chemistry Revision) useful to you.

p.s. don't email this person because its not me LOL :P

Okay... So thanks for the advice. Did you just copy this of from a site ? :/ but it has motivated me.
Wait I have done things like notes and all but I'm not quite getting the whole chapter on structure which consists of bond angles would you give any advice on that ?

Overall thanks for replying back and this has given me a better understanding. Thanks xD


This was posted from The Student Room's iPhone/iPad App

hang on a sec let me get you the one u have as hard copy

how to attach files instructions, just in case

how to attach files instructions, just in case

Need help on the types of bonds could se one tell me all the names and the angle in general. Please and thank you


This was posted from The Student Room's iPhone/iPad App

Linear shape (Straight line):
180 degrees angle.

For example:
H - H

Trigonal Planar
120 degrees angle

For example:
Aluminium Chloride
3 bonding pairs
0 lone pairs


Tetrahedral:
109.5 degrees angle.

For example:
Methane
Four bonding pairs
0 lone pairs

Octahedral:
90 degrees angle

For example:
Sulphur (VI) Fluroide
Six bonding pairs
0 lone pairs

V-Shape:
104.5 degrees angle

For example:
Water
Two bonding pairs
Two lone pairs

Trigonal Pyramidial:
107.5 degrees angle

For example:
Ammonia
Three bonding pairs
One lone pair



Aluminium chloride has no lone pairs. The bonding pairs repel each other, so the chloride atoms move as far away from each other as possible. This results in a flat shape, as, in this position, the distance between the bonding pairs is at it's greatest.
Other structures are 3D for this reason - their bonding pairs repel each other, so each atom moves as far away from each other as possible. So, the angles between each atom is identical.


Lone pairs have stronger repulsive forces than bonding pairs, as they are more electron dense.
So, lone pairs reduce the angle within a molecule.

Lone pair/Lone pair -> Lone pair/Bonding pair -> Bonding pair/Bonding pair

Each lone pair added reduces the size of the angle by 2.5 degrees.

Hi Fruity, I am sorry but I don't know a single thing about what you are talking (I am doing OCR A), the best person to ask about his would be your TEACHER and your class mates (who I am sure would be doing the same thing). Go and ask them what they are doing and any help because I am sorry but I don't know a single thing about enthalpy change :P

The other thing I had to say was that i did a bit of research for you
and found these:

Again they may or may not help !


http://store.aqa.org.uk/qual/gce/pdf/AQA-2420-W-TRB-PSA04.PDF

http://www.webchem.net/notes/how_far/enthalpy/measurement_of_enthalpy.htm

And as for what you need to know :

1. definitions
2. precautions
3. reactions
4. calculations
5. and other stuff :P (which you have to spot because I don't know about your experiment

I hope this helps
xxx

EDIT: I got a really good powerpoint slide
but I don't know how to attach

Could you email me the PowerPoint at [Removed - please use PMs], please?

does anyone know any quick methods of remembering the bonding names and how to memorised the definitions, since there are so many and also the group 2 compounds(reactions). thanx in advance for any help