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# AQA GCSE Chemistry Unit 2 24 May 2012 Watch

1. (Original post by Aidanb90)
If there is 20m of nitrogen how much hydrogen would you need? . . . 60m? anyone?
yesssss whats what i got
2. (Original post by Aidanb90)
If there is 20m of nitrogen how much hydrogen would you need? . . . 60m? anyone?
i did that
3. (Original post by osama2)
what did you get last year for chemistry?
100 UMS and 100 UMS for my ISA
4. (Original post by ryazd)
100 UMS and 100 UMS for my ISA
wowww. what mark is 100 ums in exams?
5. (Original post by Princess008)
i did that
i did that aswell :-)
6. has anyone got the unoffical mark scheme/predicted grade boundaries? i know it's probably somewhere on this thread but i can't seem to find it
7. (Original post by ryazd)
it was not 2.43

it was 4.85g

you have to divide 2 by 14 then times it by 2 because of the molar ratio

then you multiplied that by 17
No, the molar ratio did not apply here, as it was N2 by itself so it was just 28.
2g of nitrogen.
So the rest of it went 2/28 x 34 = 2.43
8. Also I think the last question about conductivity is the reaction of the metal with a non-metal in the air (which causes rust) would make an ionic compound so the electrons would be in a fixed lattice, thus unable to carry charge.
9. For the mass of nitrogen one I put 4.76....
If the answer was 4.85 (which I crossed out and stupidly rounded my numbers so I did 0.14*34 and got 4.76 instead :/ ) how many marks would I get?
But loads of people got 2.43 or something on TSR and also at my school, so I'm thinking I may be wrong? If the answer was 2.43, how many marks would I get do you think???
10. (Original post by SlayerOfTheHero)
No, the molar ratio did not apply here, as it was N2 by itself so it was just 28.
2g of nitrogen.
So the rest of it went 2/28 x 34 = 2.43
well there's another 2 marks out the window
11. (Original post by Aidanb90)
If there is 20m of nitrogen how much hydrogen would you need? . . . 60m? anyone?
Exactly what I want to know, what did everyone put for that question?
12. what do you guys reckon 100 UMS will be? i don't wanna ruin my streak!

if from these markschemes, i reckon i've gotten 39-40 for C2 and 41-42 for C3 will that give me the 200 UMS i want?
13. From the mark scheme so far i think ive got around 30-33 and there are some marks/questions missin on it.. so im hoping ive got just about an A
14. (Original post by Neeren)
Exactly what I want to know, what did everyone put for that question?
i got 60 hopefully im right
15. (Original post by SlayerOfTheHero)
No, the molar ratio did not apply here, as it was N2 by itself so it was just 28.
2g of nitrogen.
So the rest of it went 2/28 x 34 = 2.43
Yes that's right it was 2.43!!!!!!!
16. If you can post the questions you remember, I'll give my version of the answers which may be of use I think. Can't promise anything but I'm pretty confident with most of my answers (not looking to appear cocky, I find chemistry a strong point).
17. (Original post by SlayerOfTheHero)
If you can post the questions you remember, I'll give my version of the answers which may be of use I think. Can't promise anything but I'm pretty confident with most of my answers (not looking to appear cocky, I find chemistry a strong point).
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
What ion makes soluton acidic?
Which ion make soltuion alkaine?
Why do the chloride ions go to the positive electorde
Whats the mass of the gass?

Theres also some rfm question in there too but cant quite remember
18. (Original post by SlayerOfTheHero)
Also I think the last question about conductivity is the reaction of the metal with a non-metal in the air (which causes rust) would make an ionic compound so the electrons would be in a fixed lattice, thus unable to carry charge.
Metal reacts with the oxygen?, makes an ionic bond do there is less free electrons.
19. (Original post by SlayerOfTheHero)
No, the molar ratio did not apply here, as it was N2 by itself so it was just 28.
2g of nitrogen.
So the rest of it went 2/28 x 34 = 2.43
Thank god I did that!
I did the Ar of nitrogen (14) and x2
then did 2 divided by that (2/28)
then I times it by the Mr of the whole thing (34)
and I got 2.43!! YAYY!
I was so glad I got that right, I was worried about it!
20. (Original post by Chlomc)
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 manufacturers 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
What ion makes soluton acidic?
Which ion make soltuion alkaine?
Why do the chloride ions go to the positive electorde
Whats the mass of the gass?

Theres also some rfm question in there too but cant quite remember
Questions I leave out have been answered (in my opinion) correctly in the quote.

How would the results be made more percise? (1)
Using measuring instruments with smaller scale divisions.

Calculate the mean average for these results? (2)
Can't remember values, I'm sure we all got this one.

Give to examples of experimental errors that could have been made? (2)
Weighing error on the balance (scale).
Gas escaping not into the cylinder but out of the trough.

What happens in the separator?
Ammonia is condensed into a liquid which flows out.
Unreacted nitrogen and hydrogen are fed back into first stage.

Why is stage 4 needed?
Not sure, think this was the pretext on the use of compound in manufacture of food, I would assume to check it is safe.

The manufacturers increase the pressure to (high number) why dont they go over this? (1)
High pressures are expensive to maintain, also are very dangerous.

Iron surface corrodes when exposed to air, this reduces its ability to conduct, explain why? (2)
Something to do with metal reacting with something in air which forms ionic compound which means electrons are fixed in lattice, reducing effectiveness of conductivity of charge.

If there is 20m of nitrogen how much hydrogen would you need?
how much ammonia could you make with 2g of nitrogen?
2/28 then 2/28 x 34 = 2.43

Why when pressure is increase does the amount of ammonia increase?
More moles of reactants than products.

What ion makes soluton acidic?
H+

Which ion make soltuion alkaline?
OH-

Why do the chloride ions go to the positive electrode?
Negatively charged chlorine moves to positively charged electrode.

That's what I've got, feel free to comment with any rebuttal you have as I could easily be wrong.

Updated: April 30, 2015
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