AQA GCSE Chemistry Unit 2 24 May 2012
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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Re: AQA GCSE Chemistry Unit 2 24 May 2012i though this was easier tbh?(Original post by Sheel1)
Guys you have to admit this is a pretty hard paper compared to Last years so i think the grade boundary will decrease maybe like 33/45 for A* -
Re: AQA GCSE Chemistry Unit 2 24 May 2012Ca = Ca+2 + 2e- ??????(Original post by Princess008)
what did you guys get for ca= ca+2 equation -
Re: AQA GCSE Chemistry Unit 2 24 May 2012The hydrogen and nitrogen are recycled, and the iron catalyst is not used up,???(Original post by daniya12)
i put it that the costs are low as sources are readily available, and that the reaction was fairly quick.
not sure if its right though -
Re: AQA GCSE Chemistry Unit 2 24 May 2012
All the questions i can remember, theyre not in the right order and the answers im not sure about i havnt put in. but its a starting point :L
How would the results be made more percise? (1)
Giving data to 3dp rather than 2dp
Calculate the mean average for these results? (2)
Give to examples of experimental errors that could have been made? (2)
Why is it important to repeat each experiment? (1)
To get more reliable accurate results
Diagram you had to complete of N and Cl covanetly bonded together
What kind of bonding is this? (1)
Covalent bonding
Diamond are very hard, why is this. Include information on the bonding and structure of diamonds? (3)
Giant covalent bond
Particles tight together
Strong intermolecular forces
What does a precipitate recation mean?
A solid is produced
How would you get the (solid product - cant remember the name :L) seperate?
evaporation
Filtration (1)
What happens in the seperator?
Why is stage 4 needed?
If heat energy applied to this rection decreases then the amount of amonia made increases, why is this? (1)
Because its an exothermic reaction
The manu factorers increase the pressure to (high number) why dont they go over this? (1)
What is the percentage of amonia made from the possible amount? (1)
15%
Why does it not matter that its a low percentage made?
Because the unreacted nitrogen and hydrogen are recyled to go through the process again.
Explain the structure and bonding of gold? (3)
Metalic bonding
Overlapping outter shell of electrons
Delocalised electrons
Electrostatic forces
Tightly packed together particles
Why is gold a good conducture of electricity? (2)
Delocalised eclectrons
Electrons from outter shells have pathways through whole metal structure
Iron surface corrodes when exposed to air, this reduces its ability to conduct, explain why? (2)
If there is 20m of nitrogen how much hydrogen would you need?
how much ammonia could you make with 2g of nitrogen?
Why when pressure is increase does the amount of ammonia increase?
Complete this equation Ca = Ca2+ + ?
Ca = Ca2++ 2e-
Why is this described as oxidation?
Electrons are lost
Please add and contribute!Last edited by Chlomc; 24-05-2012 at 12:01. -
Re: AQA GCSE Chemistry Unit 2 24 May 2012I put that becuase its a reversible reaction, it could just be reused becuase and sent back to the start of the process.(Original post by daniya12)
i put it that the costs are low as sources are readily available, and that the reaction was fairly quick.
not sure if its right though -
Re: AQA GCSE Chemistry Unit 2 24 May 2012Thats pretty much what i put! I hope its right(Original post by daniya12)
what about the last question on why does conductivity decrease:
i put the oxygen reacts with the delocalised electrons, therefore there ar eless delocalised electrons to carry the charge hence lower conductivity -
Re: AQA GCSE Chemistry Unit 2 24 May 2012I found it hard ;L.......... I already think i lost more than 10 marks(Original post by daniya12)
i though this was easier tbh? -
Re: AQA GCSE Chemistry Unit 2 24 May 2012precipitation means it produces a solid,(Original post by Chlomc)
All the questions i can remember, theyre not in the right order and the answers im not sure about i havnt put in. but its a starting point :L
How would the results be made more percise? (1)
Giving data to 3dp rather than 2dp
Calculate the mean average for these results? (2)
Give to examples of experimental errors that could have been made? (2)
Why is it important to repeat each experiment? (1)
To get more reliable accurate results
(Picture of covalent boning) What kind of bonding is this? (1)
Covalent bonding
Diamond are very hard, why is this. Include information on the bonding and structure of diamonds? (3)
Giant covalent bond
Particles tight together
Strong intermolecular forces
What does a precipitate recation mean?
How would you get the (solid product - cant remember the name :L) seperate?
evaporation (1)
What happens in the seperator?
Why is stage 4 needed?
If heat energy applied to this rection decreases then the amount of amonia made increases, why is this? (1)
Because its an exothermic reaction
The manu factorers increase the pressure to (high number) why dont they go over this? (1)
What is the percentage of amonia made from the possible amount? (1)
15%
Why does it not matter that its a low percentage made?
Because the unreacted nitrogen and hydrogen are recyled to go through the process again.
Explain the structure and bonding of gold? (3)
Metalic bonding
Overlapping outter shell of electrons
Delocalised electrons
Electrostatic forces
Tightly packed together particles
Why is gold a good conducture of electricity? (2)
Delocalised eclectrons
Electrons from outter shells have pathways through whole metal structure
Iron surface corrodes when exposed to air, this reduces its ability to conduct, explain why? (2)
Please add and contribute!
Remove the solid from the solution by filtration -
Re: AQA GCSE Chemistry Unit 2 24 May 2012i think it is, having checked with class mates, more or less evryone put that, including the smartest girl!(Original post by Chlomc)
Thats pretty much what i put! I hope its right -
Re: AQA GCSE Chemistry Unit 2 24 May 2012It was 36 for jan 2012 and i found this much harder so im thinking around 34. Although some are saying this could be as high as 38 for A* :s(Original post by GemmaJorgensen)
How many marks about do you reckon will be needed for an A*? -
Re: AQA GCSE Chemistry Unit 2 24 May 2012im thinking around the 36/37 mark, high, yes i know, but form the looks of it, it seems the majority of people found it quite easy, then again, you never know?(Original post by GemmaJorgensen)
How many marks about do you reckon will be needed for an A*? -
Re: AQA GCSE Chemistry Unit 2 24 May 2012i said that sorry(Original post by Chlomc)
It was 36 for jan 2012 and i found this much harder so im thinking around 34. Although some are saying this could be as high as 38 for A* :s
. but lets just pray its not!
. but lets just pray its not!