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Chemistry GCSE revision HELP!!!!

I've had a week off school, and I haven't been motivated to revise at all. I've done a bit of history, geography, physics and chemistry but I haven't done enough!
Chemistry is the one I'm most worried about... I've done mock exams in class and got U on both of them, I jut can't understand anything!
I don't know what to do... I've tried but I really can't do it! Is there still hope for me not to get a U in the main exam???? :frown:

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Reply 1

OliviaBara

I'm doing OCR GCSE chemistry and I've been doing the same. Personally, I would stop worrying about it! :smile:

That is to say, just get on and do it, worrying about how little you've done will get you nowhere!

What I think you should do now, is go on to the BBC bitesize website and revise some topics on there, if you are prepared to put the time in, you will eventually understand the key concepts such as the equations; moles, emperical formulas, percentage yield. Key concepts such as the neutralisation reactions where water is made, the reactants being acids and bases (otherwise known as alkalis), the ideas of weak and strong acids and how they are defined (higher concentration of H+ ions make a stronger acid, in comparison to the OH- ions that create a weaker acid or you could say, a stronger alkaline ) revise the contact process (vannadium pentoxide is the catalyst used), fuel cells, the rusting or iron and what is done to prevent it, analgesics (drugs that are painkillers such as paracetamol, aspirin and ibuprofen, you'll need to understand their displayed formulas and perhaps the change made to aspirin to make it soluble, it is changed into a salt) covalent bonds (sharing of electrons), ionic bonding (where an ion gives up an electron to another, which then generates two ions of opposite charge- positive and negative, this forms an attraction, which holds the two together) and intermolecular bonds (van der waals force) which is basically a simple attraction of one molecule to another, although no strong bond is formed chemically. Oxidation and reduction ( remember OIL RIG- Oxidation is lost, Reduction is gained, electrons are lost in oxidation and gained in reduction) Redox reactions are reactions in which both processess occur. The hardness of water and soft water, also, temporary hardness which is caused by calcium hydrogencarbonate,calcium is responsible for hardness and sodium ions are responsible for soft water. Saponification in which soap is made and revise fats and oils which are used to make soap.Hydrolysis is the process used to turn fats into soap using sodium hydroxide. Unsaturated vegetable oils + hydrogen and a nickle catalyst --> saturated vegetable oil. Remember that, a NICKLE CATALYST.Test for unsaturation - bromine water turns from orange ---> clear. You need to know about precipitation reactions, an example would be Barium Chloride + sodium sulphate --> Barium sulphate + sodium chloride, notice the pattern that has occured in the equation. Fermentation which is the process used to make ethanol, it needs yeast as a catalyst and glucose as the solution, carbon dioxide is made. The process needs to be in the absence of oxygen as the ethanol produced would react with the oxygen (if any were to get into it) and produce ethanoic acid - vinegar in simple terms. Electrolysis and the rules of the anode and cathode - anode is always oxygen enless a halide is present, and the cathode is least reactive first (usually hydrogen). Anode is positive and the Cathode is negative. Fertilisers - you need to understand that Acid+base--> salt and water, also that Ammonia, nitrogen, sulphur and phosphorus are the key essential elements for the growth of plants, nitrogen produces proteins that plants need for growth and the others help. The haber process which makes the ammonia using nitrogen and hydrogen. You need to understand equlibrium and how pressure will drive a reaction to the side with the least amount of atoms.

The exam is on friday and what I am going to do is make a few small cards, with a card for each topic, i believe you can purchase these small lined cards from most stationary shops. They are very useful and have helped me so far in my exams. Other ways to revise would be; make posters on each topic, do past papers from the OCR website (if that is infact the exam board you are issued with) or your exam board website. I'd advise you to use their mark schemes as well. If you are still stuck then talk to your piers about the exam and perhaps get someone to test you and see how much you know :smile:

if the maths based moles questions are annoying you (for me, that's been the biggest problem) then revise that thoughroughly and PRACTICE. You can always talk to your subject teacher and I assure you they will help you in some way.

Like I said, don't worry, you still have time! Good luck.

Reply 2

Deist

You still have enough time to revise. If you don't want to get a U and you're determined enough then spend most of your time (when you get home) just doing Chemistry revision from a book.

If you want to remember formulas keep writing it down again and again until you remember it off by heart but make sure you understand the book as well as remembering it. All I can say is good luck

Reply 3

dragonkeeper999

My sister left her revision a bit last minute, and she revised by making mind maps and posters of key topics. Also, revision note cards are useful. I always read through the revision guide, make a list of anything I don't know/ understand, then make more notes and thoroughly revise these.