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Edexcel iGCSE Chemistry - 19th May 2016 - Predictions?

Hi guys,

I need to help myself focus on particular areas of Chemistry that might come up in the paper 1C on Thursday

Any predictions?

Thanks

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Reply 1

Simonovs

SO i just sat my biology edexcel core paper, and now I'm feeling pretty worried about the chemistry paper on Thursday - does anyone have any ideas or feelings on what will be in the paper?

Industrial processes and chemical tests always come up, so I'd revise those, also mole calculations and organic chemistry will probably be in there. You need to be able to label equipment. I doubt faradays will be in it a lot, but might be worth looking over them.

How did you find the bio?? Good luck on Thursday. I'll be sitting it at the same time.

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Reply 2

itsonly_sarah

Try to work on balancing equations as well, if your not good at it.
Btw I'm also sitting the chemistry exam on Thursday.Good luck

Reply 3

HKHASSAN

Original post by Simonovs

I sat the Edexcel iGCSE for Biology today.
Lots of people said they found it easy but I found it harder than I expected it to be, what with the incorporation of more demanding topics such as the menstrual cycle and nervous system. I feel as if I lost marks on the shorter, easier questions but made up for it in longer questions such as the CORMS question and natural selection one as well as the fill-in-the-gaps one.

Reply 4

Simonovs

Original post by HKHASSAN

I found menstrual cycle really hard too, and the greenhouse gases part I found really hard too.

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Reply 5

Droneon

So far, the chemistry papers have been good. I hope they don't make it hard this time.
You should revise the making salts topic, too.
By the way, I'm also sitting the Thursday Chem exam.

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Reply 6

Simonovs

Original post by Droneon

Good luck

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Reply 7

Droneon

Thanks. Good luck to you too! @Simonovs

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Reply 8

meme259

Could anyone quickly summarise how you know which salt making method to use? I know the mixing/stir/filter one is two soluble salts to make an insoluble salt, but for the others, how do you know whether to use a titration or the other method?

Reply 9

metellaest

Original post by meme259

Yes - that's the 'soluble + soluble' to make an insoluble salt (precipitate).

The other methods are:

'acid + excess base' which I think is just a solid (ie insoluble) added to an acid, which you then filter and use the four step method to obtain a pure, dry sample

'titration - between an acid and an alkali if they you don't know the concentration of one or both' - it uses a soluble base

I think it will be fairly obvious in the test, but if you have two aqueous solutions and you are obtaining a solid, do the precipitation reaction. If you have a solid and some acid, do excess base. If you have an unknown concentration of acids and/or alkalis, do a titration

Based on past papers, I'd say it's most likely to be a titration...

Good luck :smile:

(edited 7 years ago)

Reply 10

Ranveen Pandhal

@poojamakwana

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Reply 11

Droneon

(Can someone tell me how to reply to a post on TSR mobile?)

@meme259

If you're making an insoluble salt, then it's mix two aqueous solutions (one with the correct positive ion and the other with the correct negative ion) together to get an a precipitate of the insoluble salt. That would require you to know the solubilities of salts, but they are not likely to ask that in the paper.

If it's a soluble salt you're making, and if it's not SODIUM, POTASSIUM, OR AMMONIUM SALTS, then you use " acid + (excess) metal/ metal oxide/hydroxide/carbonate (cuz they're bases) " and filter out the solution formed, heat to crystallisation point, leave to form crystals and dry with blotting paper,etc.

If it's sodium, potassium or ammonium salt that you're making, then you use the titration method, where you use " acid + sodium/potassium hydroxide/carbonate OR Ammonia solution (bases) " to find the exact vol. of alkali needed to neutralise a known vol. of acid. using an indicator. Then use those noted-down volumes to make the salt by crystallisation, drying...etc.

You'll most probably know what kind of salt you have to make, they'll most likely tell it in the question, so you just have to keep the method in mind.

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Thnks Ranveen

(copying to all iGCSE Chem threads :biggrin:

)

could anyone help me out with explaining this: (general topic of polymerisation, additional polymerisation etc. The question itself made me go whaaaaat? and I just guessed because it's better than a blank amirite the Gold is me marking and my expression of ~woe~ THANKS IN ADVANCE I REALLY NEED HELP >.< )