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AQA CHEM2 ~ May 23rd 2012 ~ AS Chemistry

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Reply 40
:0 same
Reply 41
Whats the hardest topic in CHEM2? Nothing we've done seems like that hard lol.
Reply 42
doing equilibria(maybe spelt it wrong lol) starting redox soon :smile:
Reply 43
Can't believe there's a thread for this already :tongue:
I'm finding it alright at the moment. We haven't been going through the syllabus in order though, so we may be leaving all the hard stuff until the end :frown:
I've snored my way through Kinetics and Energetics so far. I'm rather sure we should've covered more than this as well, and so I expect my teacher to rush us through it as per usual once we get back from half-term.
Mechanism :sigh:
Reply 46
hate energetics, so many definitions to remember and that hess's law **** is effort
Reply 47
Everything has been E.Z so far :/

lol
Reply 48
Original post by cuckoo99
hate energetics, so many definitions to remember and that hess's law **** is effort


All definitions you need are for Energetics pretty much are:

- Enthalpy Change
- Enthalpy of Formation
- Enthalpy of Combustion
- Hess's Law
- State the Standard Conditions
- Mean Bond Enthalpy

And know Exothermic is energy given out, Endothermic is energy taken in.
Know that Q=mc/\T (mc delta t), /\H=Q/moles.
Reply 49
TOPIC 2.1 - ENERGETICS

Exothermic - Give out heat (NEGATIVE) - /\H is NEGATIVE
Endothermic - Take in heat (POSITIVE) - /\H is POSITIVE

/\H - Enthalpy Change - The Enthalpy change for a reaction is the heat energy change measured under conditions of constant pressure.

The Standard Enthalpy Change for a reaction is the heat energy change measured under standard conditions: 100kPa and 298K (and all reactants+products in their standard states).

Enthalpy changes are measured in kJmol -1

So /\H= heat energy change/no. moles (/\H= Q/mol)


STANDARD ENTHALPY OF FORMATION - The Enthalpy change, under standard conditions, when 1 mole of compound is formed from it's elements with all reactants and products in their standard states.

STANDARD ENTHALPY OF COMBUSTION - The Enthalpy change, under standard conditions, when 1 mole of substance is burnt in excess Oxygen, with all reactants and products in their standard states.

----- THE STANDARD ENTHALPY OF FORMATION OF ALL ELEMENTS IN THEIR STANDARD STATES IS 0 -----
(edited 12 years ago)
Reply 50
CHEM 4 is the hardest module CHEM 2 is fairly standard
Reply 51
Original post by Sorro10
Everything has been E.Z so far :/

lol


I know. I keep waiting for it to get hard and it isn't... :dontknow:
Reply 52
now doing Halogens, pretty standard. more of a carry on from gcse :smile:
Reply 53
Original post by cuckoo99
now doing Halogens, pretty standard. more of a carry on from gcse :smile:


Yea lol
We've just done Free Radical Substitution & Nucleophilic Substitution with one teacher and we're STILL doing Energetics with the other .__.
Reply 55
Nope ;/
Reply 56
Anyone done the A2 ISA yet for unit 6?
Reply 57
I have my written ISA paper on tuesday, and as far as I can gather from past papers and what the teachers have said, the task is 'to identify the metal ion in a salt, used as a de-icer by a series of observation exercises'
The main areas of the AQA specification (which is online) that you need to look up are 3.1.2 (amount of substance), 3.2.1 (energetics), 3.2.5 (group 7 (17) the halogens), 3.2.6 (group 2, the alkaline earth metals). Not all of this will come up obviously, however I'm still going to revise it all as much as possible in case.
And if you're working out of the AQA textbook chapter 7, 11 and 12 are the ones to look over apparently :smile:
good luck to everyone, hope it all goes well
Reply 58
Almost finished CHEM2 like 2 topics left lol.
Reply 59
Original post by mybubbles
I have my written ISA paper on tuesday, and as far as I can gather from past papers and what the teachers have said, the task is 'to identify the metal ion in a salt, used as a de-icer by a series of observation exercises'
The main areas of the AQA specification (which is online) that you need to look up are 3.1.2 (amount of substance), 3.2.1 (energetics), 3.2.5 (group 7 (17) the halogens), 3.2.6 (group 2, the alkaline earth metals). Not all of this will come up obviously, however I'm still going to revise it all as much as possible in case.
And if you're working out of the AQA textbook chapter 7, 11 and 12 are the ones to look over apparently :smile:
good luck to everyone, hope it all goes well

Ohhh is this the second ISA, have you done your first ISA? :s-smilie:

Original post by Sorro10
Almost finished CHEM2 like 2 topics left lol.


Good to hear :tongue: Keep up the hard work! Ace CHEM2 and all your Chemistry worries can be laid to rest, CHEM2 is worth the MOST UMS. Worth 20 more UMS in total than any A2 mod! :biggrin: Get to working!!

PS if anyone needs help etc, let me know! i have a TON of helpful stuff :biggrin:

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