Turn on thread page Beta
    • Thread Starter
    Offline

    13
    ReputationRep:
    Rather than making two threads, I thought I'd just make the one for both of the exams.

    Exam information:

    C1, C2 and C3 - 6th June (PM)

    C4, C5 and C6 + data analysis - 16th June (AM)

    I got these all wrong for biology, but I think I might get them right now - my predictions for the six mark questions:

    C1 - Smells - something to do with perfumes, maybe esters or their volatility

    C2 - Haber process - state the equation and explain the conditions

    C3 - Exothermic and endothermic reactions OR allotropes of carbon/nanotechnology

    C4 - explaining one of the types of bonding (maybe metallic) or comparing them, though it could simply be purifying and testing water.

    C5 - strong and weak acids: give the equations and then explain the differences

    C6 - depletion of the ozone layer (give the equations) and explain the consequences of this

    I think displacement comes up for C4, C5 and C6, so I would definitely recommended revising that, as it might feature as part of a 6 mark question.

    These are likely to be wrong, but it's just a suggestion, eh?

    I'll post resources on here soon

    How is everyone getting in with their revision, by the way?



    Posted from TSR Mobile
    Offline

    3
    ReputationRep:
    Hopefully this exam will go well, like biology
    • Thread Starter
    Offline

    13
    ReputationRep:
    (Original post by Pikki1234)
    Hopefully this exam will go well, like biology
    Hopefully, how are you revising?


    Posted from TSR Mobile
    Offline

    3
    ReputationRep:
    (Original post by kingaaran)
    Hopefully, how are you revising?


    Posted from TSR Mobile
    Just trying to do as many past papers. What about you?
    • Thread Starter
    Offline

    13
    ReputationRep:
    (Original post by Pikki1234)
    Just trying to do as many past papers. What about you?
    Same, and I'm making sure I know all aspects of the specification.


    Posted from TSR Mobile
    Offline

    0
    ReputationRep:
    How is revision, guys? The grade boundaries are quite low for science so we should be fine anyway (:
    Offline

    2
    ReputationRep:
    (Original post by kingaaran)
    ....I'll post resources on here soon

    How is everyone getting in with their revision, by the way?



    Posted from TSR Mobile
    Are there any resources you can provide?
    Thanks
    Offline

    14
    ReputationRep:
    Someone please help with harber process, electrolysis of brine and normal electrolysis, esters


    Posted from TSR Mobile
    Offline

    0
    ReputationRep:
    Chemistry have the highest grade boundaries of all science topics. So its best not to rely on low grade boundaries. Anyway, an A* is 360/400 UMS. It means that you have to basically get A* in both papers, unless you get a high A* in CA, which gives you some opportunity to get an A in one exam and still get an A* overall.
    :rolleyes:
    • Thread Starter
    Offline

    13
    ReputationRep:
    (Original post by lowhigh)
    Are there any resources you can provide?
    Thanks
    What would you like, as I can then try to find it? I have 6 mark questions for every topic in C1, C2 and C3, which I have attached. I have marked exemplar answers to them, if you would like them too?
    Attached Files
  1. File Type: docx Practise with 6 markers.docx (18.2 KB, 393 views)
  2. File Type: docx Chemistry - Topics.docx (16.4 KB, 238 views)
    • Thread Starter
    Offline

    13
    ReputationRep:
    (Original post by kandykissesxox)
    Someone please help with harber process, electrolysis of brine and normal electrolysis, esters


    Posted from TSR Mobile
    Haber process

    This is used to manufacture ammonia. It uses nitrogen and hydrogen to do this. This is easy to remember, as the molecular formula for ammonia is NH3, so you can see that there is nitrogen and hydrogen going in there. In the Haber process, all that happens is that you take the nitrogen and hydrogen and react them together:

    Nitrogen + Hydrogen <--> Ammonia
    N2 + 3H2 <-->2NH3

    However, you can't just put them together and expect to get ammonia instantly, as the particles will take awhile to react, so we add some conditions to speed this up, increase the yield (how much is produced) and lower the building costs: iron catalyst, high pressure, temperature of 450 degrees and a recycling tube, where unreacted nitrogen and hydrogen are recycled.

    All you need to know now is why these conditions are used:

    A high pressure is used to increase the percentage yield of ammonia, but it's not too high, as that will mean that the building costs will be high and there could be the chance of an explosion.

    A high temperature is used to increase the rate of reaction, but it's not too high otherwise the yield would be too low, as the reaction will start to go backwards, as it's reversible - you don't really need to know the last bit, but it's good to know anyways, as you'll need it for C5.

    A catalyst is used to increase the rate of reaction without changing the yield. It doesn't change the yield, as it doesn't take part in the reaction itself.

    If you're wondering why unreacted nitrogen and hydrogen is recycled, well, think to yourself, if they weren't recycled, what would happen to them? Nothing! They'd be wasted. Hence, by recycling them, the amount of waste products produced is reduced, increasing the efficiency of the reaction.

    Another bit of detail that you need to know is why is ammonia important for the world food production: all of the crops that are grown in the world require nitrogen and most of this comes from artificial fertilisers. But guess what? The first step of making most of these fertilisers is the Haber process, which is why the production of ammonia is so important.

    I'll do the rest of the topics in a bit
    • Thread Starter
    Offline

    13
    ReputationRep:
    (Original post by kandykissesxox)
    Someone please help with harber process, electrolysis of brine and normal electrolysis, esters


    Posted from TSR Mobile
    Electrolysis of brine can be complicated and I only started to understand electrolysis after having done it in C6

    Read on here
    Saying that, it's not actually that hard once you understand what is happening - you have to understand it, don't memorise it, as you're more prone to forgetting it in the exam.

    Basically, what happens is that you have your two electrodes - a cathode (negatively charged) and an anode (positively charged), the way I remember it is that 'a' comes before 'c' in the alphabet, so the anode must the positive, as the positive numbers are bigger than the negative ones - I know, a bit weird, eh?

    You also have an electrolyte and, in this case, the electrolyte is aqueous (dissolved in water) sodium chloride (brine), which contains these ions: Na+, Cl-, H+ and OH-. You should know the charges by now, or how to work them out, but if you don't, now's the time to get learning

    If the cathode is negative, it's going to attract all of the positive ions, so the Na+ and the H+ ions. However, the sodium ion doesn't discharge from the cathode - only the hydrogen ion does - you don't need to know why. Hence, the hydrogen ion gains electrons - because it's positively charged, which means it has more positive protons than negative electrons - becomes a gas and escapes.

    At the anode, the chloride ion will lose an electron - because it's negatively charged, which means it has more negative electrons than positive protons - to become chlorine gas and will be discharged, while the hydroxide ion doesn't discharge from the anode - don't need to know why - so just remains in solution.

    In the solution, you will have a collection of sodium and hydroxide ions, as they haven't been discharged, which combine to form sodium hydroxide.

    You just need to be able to write the half-equations too:

    Cathode (chlorine given off):


    2Cl- - 2e- --> Cl2(sorry about the superscript and subscript - blame TSR!)


    Remember, chlorine gas always goes around in pairs, as Cl2, so you must ensure that you have two chlorine ions each losing (hence the minus) an electron to form chlorine gas.



    Anode


    2H+ + 2e- --> H2 (sorry about the superscript and subscript - blame TSR!)

    Like with chlorine, hydrogen gas goes around with pairs, so you need two hydrogen atoms (which gains two electrons, hence the plus) to give the hydrogen gas





    This one is about esters

    Read more about esters


    You need to know the following equation:

    Acid + Alcohol --> Ester + Water

    So, if they give you an acid and an alcohol, you should be able to state the name of the ester and if they give you an ester, you should be able to state the name of the acid and alcohol. For example, if I reacted ethanol (alcohol) with butanoic acid, I would get ethyl butanoate. You just need to be able to spot the trend, as then it'll become quite easy to state the ester.

    The only other thing you need to know about esters is that they can be used as solvents.

    The other thing they can test you on is interpreting data on the usefulness of different esters as solvents, as they did in June 2013, but you don't need to be able to recall anything for that - just be able to interpret data.

    That's all you need to know on esters.



    Hope it helps!
    Offline

    10
    ReputationRep:
    I'm in this!

    The test tomorrow shouldn't be bad, just need to go over a few topics to refresh memory. C4C5C6 could be a monster though
    Offline

    14
    ReputationRep:
    (Original post by kingaaran)
    Haber process

    This is used to manufacture ammonia. It uses nitrogen and hydrogen to do this. This is easy to remember, as the molecular formula for ammonia is NH3, so you can see that there is nitrogen and hydrogen going in there. In the Haber process, all that happens is that you take the nitrogen and hydrogen and react them together:

    Nitrogen + Hydrogen <--> Ammonia
    N2 + 3H2 <-->2NH3

    However, you can't just put them together and expect to get ammonia instantly, as the particles will take awhile to react, so we add some conditions to speed this up, increase the yield (how much is produced) and lower the building costs: iron catalyst, high pressure, temperature of 450 degrees and a recycling tube, where unreacted nitrogen and hydrogen are recycled.

    All you need to know now is why these conditions are used:

    A high pressure is used to increase the percentage yield of ammonia, but it's not too high, as that will mean that the building costs will be high and there could be the chance of an explosion.

    A high temperature is used to increase the rate of reaction, but it's not too high otherwise the yield would be too low, as the reaction will start to go backwards, as it's reversible - you don't really need to know the last bit, but it's good to know anyways, as you'll need it for C5.

    A catalyst is used to increase the rate of reaction without changing the yield. It doesn't change the yield, as it doesn't take part in the reaction itself.

    If you're wondering why unreacted nitrogen and hydrogen is recycled, well, think to yourself, if they weren't recycled, what would happen to them? Nothing! They'd be wasted. Hence, by recycling them, the amount of waste products produced is reduced, increasing the efficiency of the reaction.

    Another bit of detail that you need to know is why is ammonia important for the world food production: all of the crops that are grown in the world require nitrogen and most of this comes from artificial fertilisers. But guess what? The first step of making most of these fertilisers is the Haber process, which is why the production of ammonia is so important.

    I'll do the rest of the topics in a bit

    thanks for the help i was just wondering can i have some help on esters, polymers, alkanes and alkenes, electrolysis and bucky balls please
    • Thread Starter
    Offline

    13
    ReputationRep:
    (Original post by kandykissesxox)
    thanks for the help i was just wondering can i have some help on esters, polymers, alkanes and alkenes, electrolysis and bucky balls please
    I posted above


    Posted from TSR Mobile
    Offline

    1
    ReputationRep:
    (Original post by kingaaran)
    I posted above


    Posted from TSR Mobile
    Do you want to skype later to revise?
    Offline

    2
    ReputationRep:
    (Original post by kingaaran)
    What would you like, as I can then try to find it? I have 6 mark questions for every topic in C1, C2 and C3, which I have attached. I have marked exemplar answers to them, if you would like them too?
    This is very helpful thanks. The exemplar answers would be nice too.
    Offline

    14
    ReputationRep:
    (Original post by kingaaran)
    I posted above


    Posted from TSR Mobile

    hi can i have all of the 6 markers you have for c1-3 with answers please?
    Offline

    2
    ReputationRep:
    (Original post by kingaaran)
    C1 - Smells - something to do with perfumes, maybe esters or their volatility

    C2 - Haber process - state the equation and explain the conditions

    C3 - Exothermic and endothermic reactions OR allotropes of carbon/nanotechnology
    Esters came up on the January 2013 exam paper so i doubt it'll appear again..
    Offline

    3
    ReputationRep:
    I think a six mark could be about the evolution of the atmosphere...hate that
 
 
 
The home of Results and Clearing

1,230

people online now

1,567,000

students helped last year

University open days

  1. Bournemouth University
    Clearing Open Day Undergraduate
    Fri, 17 Aug '18
  2. University of Bolton
    Undergraduate Open Day Undergraduate
    Fri, 17 Aug '18
  3. Bishop Grosseteste University
    All Courses Undergraduate
    Fri, 17 Aug '18
Poll
Will you be tempted to trade up and get out of your firm offer on results day?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.