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AQA Chemistry Unit 2 (resit) CHEM2 10th June

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Hows everyone with Hess's Law?
Reply 21
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man i
3
Original post by Sheary13
Hows everyone with Hess's Law?


im ok with it, as long as they don't come out with the next random questions it shouldn't be hard, why?
Aqa....
Physics unit 2 resit exam: Solid, unlike any past papers
Biology unit 2 resit exam: Solid, unlike any past papers
Anyone want to guess what's going to go down tomorrow?
Reply 23
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man i
3
Original post by Ninjakam119
Aqa....
Physics unit 2 resit exam: Solid, unlike any past papers
Biology unit 2 resit exam: Solid, unlike any past papers
Anyone want to guess what's going to go down tomorrow?


tbf unit 1 was ok but they could end up putting some next question in for unit 2 as long as its not maxwells disitribution im ok
what does the 'most probable energy' represent on maxwells distribution
Reply 25
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sean.17
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They did put some odd questions on CHEM 1 such as the one asking how VDW arise.. I have a feeling they are gonna do exactly the same for this paper :redface:
Reply 26
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sean.17
1
Original post by Jophilip123
what does the 'most probable energy' represent on maxwells distribution


the energy that the majority of particles have, basically
Which past paper do people recommend doing ?! Which one is hardest?
Reply 28
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Original post by kother2015
Which past paper do people recommend doing ?! Which one is hardest?


More recent ones, I'd say the last two so 2014 and 2015
Anyone feel like last year's paper wasn't even that bad and hating themselves for screwing it up?? I am lol
Original post by lahigueraxxx
Anyone feel like last year's paper wasn't even that bad and hating themselves for screwing it up?? I am lol

Me too. Although I didn't have the knowledge base I have this year thanks to revision and CHEM4 and 5 with regards to chemistry so hopefully I wont make the stupid mistakes I did last year. At the moment I'm just expecting the worst and hoping to be plesantly surprised. Oh and I came across an obscure question the other day but since its only come up once I'm thinking it might come up again. Beryllium and aluminium chloride are covalent because the beryllium and aluminium have a high charge density so attract the electrons away from the chlorine (AQA said polarises CL-) making a covalent bond rather than ionic like you'd expect. Just figured I'd mention it since I didn't know that till yesterday and I figured that might mean other people also don't know.
Reply 31
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man i
3
the problem with chem 2 is that its easy to make small mistakes i done the june 2015 paper 2 days ago got 76 but lost 10 marks for simple arithmetic errors.
Reply 32
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NuzAsk
Guys when can u put the reversible sign when writing an equation of chlorine and water?
Original post by NuzAsk
Guys when can u put the reversible sign when writing an equation of chlorine and water?


When it says give the equilibrium formed..or along those lines..it was in a past paper not too long ago. If it just says reaction between Chlorine and water, go for the standard.
Original post by ChaoticParadigm
Me too. Although I didn't have the knowledge base I have this year thanks to revision and CHEM4 and 5 with regards to chemistry so hopefully I wont make the stupid mistakes I did last year. At the moment I'm just expecting the worst and hoping to be plesantly surprised. Oh and I came across an obscure question the other day but since its only come up once I'm thinking it might come up again. Beryllium and aluminium chloride are covalent because the beryllium and aluminium have a high charge density so attract the electrons away from the chlorine (AQA said polarises CL-) making a covalent bond rather than ionic like you'd expect. Just figured I'd mention it since I didn't know that till yesterday and I figured that might mean other people also don't know.


Omg thats such a werid questions! Thanks so much ill just learn it since the meaning is strange lolz
Reply 35
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man i
3
you'll need to know it for chem 5 anyway

Original post by Aliceeee12
Omg thats such a werid questions! Thanks so much ill just learn it since the meaning is strange lolz
Original post by man i
you'll need to know it for chem 5 anyway


Aaah im having trouble understanding it U5 rev later hahah
So I thought I'd write this question as I wouldn't necessarily know how to do it straight away upon first glance

) A 25.0 cm3 sample of 2.00 mol dm–3 hydrochloric acid was mixed with 50.0 cm3 of a1.00 mol dm–3 solution of sodium hydroxide. Both solutions were initially at 18.0 °C.After mixing, the temperature of the final solution was 26.5 °C.Use this information to calculate a value for the standard enthalpy change for thefollowing reaction.HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l)In your calculation, assume that the density of the final solution is 1.00 g cm–3 and thatits specific heat capacity is the same as that of water. (Ignore the heat capacity of thecontainer.)...............................................................

Energy absorbed (q) = Mass of Solution X Heat Capacity X Temperature change

- You use mass of both solutions combines (each cm cubed is roughly a gram) (25+50= 75)
- Temp change = 26.5-18 = 8.5

So 75 x 4.18 X 8.5 = 2665
you use moles of whatever is not in XS - so the lowest value. In this case, both are 0.05 so that's what we use

Enthalpy change = Q/No of Moles
Therefore -2665/0105

= -53.4 Kjmol-1
Original post by ChaoticParadigm
Me too. Although I didn't have the knowledge base I have this year thanks to revision and CHEM4 and 5 with regards to chemistry so hopefully I wont make the stupid mistakes I did last year. At the moment I'm just expecting the worst and hoping to be plesantly surprised. Oh and I came across an obscure question the other day but since its only come up once I'm thinking it might come up again. Beryllium and aluminium chloride are covalent because the beryllium and aluminium have a high charge density so attract the electrons away from the chlorine (AQA said polarises CL-) making a covalent bond rather than ionic like you'd expect. Just figured I'd mention it since I didn't know that till yesterday and I figured that might mean other people also don't know.


Wow that really is an obscure question.. Thank you for sharing!
I just want to get this over + done with now tbh. - too tired to do anymore stuff. ):

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