GCSE Chemistry Unit 2 and Unit 3 C2 C3 24th May 2012 Exam Discussion
Chemistry exam discussion - share revision tips in preparation for GCSE, A Level and other chemistry exams and discuss how they went afterwards.
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GCSE Chemistry Unit 2 and Unit 3 C2 C3 24th May 2012 Exam Discussion
Havent seen a discussion topic for this. So how you guys revising? What are you mainly focusing on? Any tips on these particular exams?
Got a C and a B, need to improve them to A's so i can get an A overall
Start helping and discussing guys! Exam next week!Last edited by zabi1; 17-05-2012 at 19:41. -
Re: GCSE Chemistry Unit 2 and Unit 3 C2 C3 24th May 2012 Exam Discussionnice to know, how are you revising for these papers? and what do you think most likely will come up?
ATM the tricky one is remembering the flame test colours
but other than that, the equations im ok with and the rest of the info hopes sticks into my brain -
I'm sure electrolysis, empirical formula, reversible reactions (i.e. The haber process) and some sort of analysing substances question will come up to test/adapt our knowledge to example an experiment they give us.(Original post by zabi1)
nice to know, how are you revising for these papers? and what do you think most likely will come up?
ATM the tricky one is remembering the flame test colours
but other than that, the equations im ok with and the rest of the info hopes sticks into my brain
I have the AQA revision guide and it's great, it has everything you need to know so i recommend you get one if you don't have it already!
Also, i hope they don't put too much about the haber process on cos it really confuses me, especially when you have to explain the conditions and how to get an optimum yield of ammonia :/ and yeah, i find the flame test colours confusing too!
This was posted from The Student Room's iPhone/iPad App -
Re: GCSE Chemistry Unit 2 and Unit 3 C2 C3 24th May 2012 Exam DiscussionSame! the optimum yield of ammonia is confusing, the rest is just remembering the key points of each topic and feeding them to your brain,(Original post by EmineF)
I'm sure electrolysis, empirical formula, reversible reactions (i.e. The haber process) and some sort of analysing substances question will come up to test/adapt our knowledge to example an experiment they give us.
I have the AQA revision guide and it's great, it has everything you need to know so i recommend you get one if you don't have it already!
Also, i hope they don't put too much about the haber process on cos it really confuses me, especially when you have to explain the conditions and how to get an optimum yield of ammonia :/ and yeah, i find the flame test colours confusing too!
This was posted from The Student Room's iPhone/iPad App
anyone else on tsr doing these exams
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Re: GCSE Chemistry Unit 2 and Unit 3 C2 C3 24th May 2012 Exam DiscussionAccording to my revision guide, these are all the tests (ion and flame) we need to know:(Original post by PrinceyJ)
Does anybody know which flame tests colours and ion tests we need to know for unit 3?
So far I've noted down Calcium, Potassium, Lithium, Sodium and Magnesium.
Spoiler:ShowFlame tests:
Dip nichrome wire into concentrated hydrochloric acid to clean it. Then dipped into compound. Put over blue flame, the flame should change colour depending on the compound, and goes as such:
Lithium: red
Sodium: yellow
Potassium: lilac
Calcium: brick red
Barium: apple green
Copper: blue-green
Carbonates + dilute acid:
Forms carbon dioxide gas.
Eg: Calcium Carbonate + Dilute Hydrochloric Acid -------> Calcium Chloride + Carbon Dioxide + Water
Thermal Decomposition of Copper and Zinc Carbonate:
You put the carbonates over a bunsen flame...
Copper Carbonate (green) -------> Copper Oxide (black) + Carbon Dioxide
Zinc Carbonate (white) ----------> Zinc Oxide (yellow) + Carbon Dioxide
Metal Ions:
(The colours in the brackets are the colour of the precipitates formed)
Aluminium (Al3+) + Sodium Hydroxide ----> Aluminium Hydroxide (white)
Calcium (Ca2+) + Sodium Hydroxide ----> Calcium Hydroxide (white)
Magnesium (Mg2+) + Sodium Hydroxide ----> Magnesium Hydroxide (white)
Copper (Cu2+) + Sodium Hydroxide ----> Copper Hydroxide (blue)
Iron (Fe2+) + Sodium Hydroxide ----> Iron Hydroxide (green)
Iron (Fe3+) + Sodium Hydroxide ----> Iron Hydroxide (brown)
Sulfate Ion + Barium chloride solution + dilute hydrochloric acid ---> Barium sulfate (white)
Nitrate Ion + aluminium powder + sodium hydroxide solution ---> ammonia (turns damp litmus paper blue)
Chloride Ion + silver nitrate solution + nitric acid ---> Silver chloride (white)
Bromide Ion + silver nitrate solution + nitric acid ---> Silver bromide (cream)
Iodide Ion + silver nitrate solution + nitric acid ---> Silver bromide (yellow)
I think that's all of it!
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Re: GCSE Chemistry Unit 2 and Unit 3 C2 C3 24th May 2012 Exam DiscussionThat's great, thanks!(Original post by Koroviev)
According to my revision guide, these are all the tests (ion and flame) we need to know:
Spoiler:ShowFlame tests:
Dip nichrome wire into concentrated hydrochloric acid to clean it. Then dipped into compound. Put over blue flame, the flame should change colour depending on the compound, and goes as such:
Lithium: red
Sodium: yellow
Potassium: lilac
Calcium: brick red
Barium: apple green
Copper: blue-green
Carbonates + dilute acid:
Forms carbon dioxide gas.
Eg: Calcium Carbonate + Dilute Hydrochloric Acid -------> Calcium Chloride + Carbon Dioxide + Water
Thermal Decomposition of Copper and Zinc Carbonate:
You put the carbonates over a bunsen flame...
Copper Carbonate (green) -------> Copper Oxide (black) + Carbon Dioxide
Zinc Carbonate (white) ----------> Zinc Oxide (yellow) + Carbon Dioxide
Metal Ions:
(The colours in the brackets are the colour of the precipitates formed)
Aluminium (Al3+) + Sodium Hydroxide ----> Aluminium Hydroxide (white)
Calcium (Ca2+) + Sodium Hydroxide ----> Calcium Hydroxide (white)
Magnesium (Mg2+) + Sodium Hydroxide ----> Magnesium Hydroxide (white)
Copper (Cu2+) + Sodium Hydroxide ----> Copper Hydroxide (blue)
Iron (Fe2+) + Sodium Hydroxide ----> Iron Hydroxide (green)
Iron (Fe3+) + Sodium Hydroxide ----> Iron Hydroxide (brown)
Sulfate Ion + Barium chloride solution + dilute hydrochloric acid ---> Barium sulfate (white)
Nitrate Ion + aluminium powder + sodium hydroxide solution ---> ammonia (turns damp litmus paper blue)
Chloride Ion + silver nitrate solution + nitric acid ---> Silver chloride (white)
Bromide Ion + silver nitrate solution + nitric acid ---> Silver bromide (cream)
Iodide Ion + silver nitrate solution + nitric acid ---> Silver bromide (yellow)
I think that's all of it!
They weren't in my CGP revision guide (or I couldn't find them).
Just done a unit 3 past paper, 40/45 yay. -
Re: GCSE Chemistry Unit 2 and Unit 3 C2 C3 24th May 2012 Exam Discussion
I think we need to know like mass spectrometry, infra red spectrometry and atomic absorption spectroscopy but i don't know in how much detail? Does anyone know of any others we need to learn?
My teacher said it isn't one of the most important thins to revise so i'm not going to worry about it too much
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Re: GCSE Chemistry Unit 2 and Unit 3 C2 C3 24th May 2012 Exam DiscussionI have both jan 2012 copies but only hard copies i think the january 2012 C3 was quite hard so fingers crossed this one will be easy for us(Original post by vxrz)
Guys... who's got the Jan 2012 papers?!?!?
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Re: GCSE Chemistry Unit 2 and Unit 3 C2 C3 24th May 2012 Exam DiscussionAhhh.. what a shame(Original post by sophie5)
I have both jan 2012 copies but only hard copies i think the january 2012 C3 was quite hard so fingers crossed this one will be easy for us
quite desperate for these as well.
Anyone?


I an quite scared cause overall out off all the science's chemistry is my lowest score:/ And I find this topic difficult!