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OCR 21st Century Science C4 C5 C6 14th June 2016 Discussion thread

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I reckon endo and exothermic reactions or titration as 6 markers for c6
Reply 21
Original post by Char4ncubex
Here's my take on it....

Basically electrolysis is used to separate ionic compounds that cannot be separated by carbon as they are more reactive than carbon, for example aluminium (Al3O2). Electrolysis used electricity to chemically decompose the ionic compound to get the pure form eg to separate the aluminium from the oxygen as we want to use aluminium. The aluminium (called the electrolyte) needs to be molten so that the ions are a free to move and can complete the circuit. The aluminium ions are positively charged and move to the negative electrode called the cathode. Here the aluminium ions gain electrons to become neutral aluminium atoms. Whereas at the positive electrode (the anode) negatively charged oxygen ions move here and lose electrons to become neutral and oxygen atoms. The aluminium is pure and is now separated from the oxygen.Aluminium is in group 3 so it has a 3+ charge, therefore it needs 3 electrons to become neutral.Oxygen has a -2 charge so needs to lose 2 electrons to become neutral. Don't forget that oxygen is a diatomic molecule so at the end you'll need to write O + O = O2.

I hope I explained alright and it helps


Thankyou this is very helpful.
what are your predictions for the 6 mark questions ?
Reply 22
What is c5 even about?:K:
Reply 23
Original post by Billy.b
What is c5 even about?:K:


Recycling metals, melting points, hydrospheres and lithoshperes, bondings, testing for sulfates/carbonates... such fun.
Reply 24
Original post by zo26blue
Recycling metals, melting points, hydrospheres and lithoshperes, bondings, testing for sulfates/carbonates... such fun.


thank you!! and tell me about it:unimpressed:
Can someone help me wih the last point of c5 in specification where it talks about the impacts of metal use and production and stuff


Posted from TSR Mobile
Original post by shanz123
Can someone help me wih the last point of c5 in specification where it talks about the impacts of metal use and production and stuff


Posted from TSR Mobile


I'm assuming that's about the effect of mining ores on the environment? You could talk about the benefits of jobs/transport/useful metal products made however there are negative impacts e.g. high energy use/toxic fumes when extracting metals/ landscape and habitat destruction/ mine shafts can be dangerous.
This is very brief but hope it helps :biggrin:
Original post by HateOCR
haha my school made me do chemistry and physics last year (im doing my biology triple this year). So happy the stress is gone however i wont lie the 2015 paper was much harder than the 2016 ones


So when did you do core?
Original post by MezmorisedPotato
Discuss predictions and tips here.
I will post resources later.
Good luck :smile:

When are you posting the resources?
Guys! I'm so worried! I don't know much about chemistry I revised so much but I just forget it
My personal predictions are

C4 - Mendeleev,Newlands and Dobereiner or Ions
C5 - Different types of bonds so ionic, metallic and covalent - sim and differences or Electrolysis
C6 - Rates of reaction or Titrations
Original post by Wisdom2
My personal predictions are

C4 - Mendeleev,Newlands and Dobereiner or Ions
C5 - Different types of bonds so ionic, metallic and covalent - sim and differences or Electrolysis
C6 - Rates of reaction or Titrations


Oh goddddd :frown:
Those C6 predictions are my absolute worst nightmare! If titrations come up I will honestly hit my head on the desk :frown:

Can't we just have a nice one on diamond vs graphite for C5 :colondollar:
Original post by Wisdom2
My personal predictions are

C4 - Mendeleev,Newlands and Dobereiner or Ions
C5 - Different types of bonds so ionic, metallic and covalent - sim and differences or Electrolysis
C6 - Rates of reaction or Titrations


Nice predictions! What do you mean by "sim and differences or Electrolysis" ??
Original post by NiamhM1801
Oh goddddd :frown:
Those C6 predictions are my absolute worst nightmare! If titrations come up I will honestly hit my head on the desk :frown:

Can't we just have a nice one on diamond vs graphite for C5 :colondollar:


Ahah I love rates of reactions. But yeah for C5 if graphite/diamond came up I would loooove that! :elmo: I really hate those mathsy ones :frown: uh and i hate testing for ions too
Original post by Ella_08
Nice predictions! What do you mean by "sim and differences or Electrolysis" ??


Think he meant similarities and differences between ionic, metallic and covalent bonds
Original post by Ella_08
Ahah I love rates of reactions. But yeah for C5 if graphite/diamond came up I would loooove that! :elmo: I really hate those mathsy ones :frown: uh and i hate testing for ions too


Hm I guess rate of reaction isn't that bad, it's titrations that really get to me. Same haha, although I don't mind mathsy ones too much. Oh god testing for ions would be dreadful too!
I feel like the only thing I'm prepared for for this exam is C4 lmao
Original post by NiamhM1801
Think he meant similarities and differences between ionic, metallic and covalent bonds


Yup!
Original post by Steampunk_Turtle
When are you posting the resources?


Adding now
Original post by NiamhM1801
Think he meant similarities and differences between ionic, metallic and covalent bonds


Original post by NiamhM1801
Hm I guess rate of reaction isn't that bad, it's titrations that really get to me. Same haha, although I don't mind mathsy ones too much. Oh god testing for ions would be dreadful too!
I feel like the only thing I'm prepared for for this exam is C4 lmao


oh right, i thought he made a typo and meant 'sim/diff of electrolysis, my bad :biggrin: Uh tell me about it, i hate titrations. I'm cramming everything now, havent even got to that lool. At least you feel confident about some of it, the only stuff i like is the environment, graphite/diamond and history of periodic table. I'm screwed with C456 basically but i did well on C123 so it should be ok :dontknow: good luck to you :smile:
Original post by Ben ESC
I reckon endo and exothermic reactions or titration as 6 markers for c6


Let's hope it's endo/exothermic reactions :yeah:

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