[JamilMCR]

Just wondering if anyone has any tips on how to revise for the chemistry empa (Unit 3) for AQA or if anyone has had the test already? Any help will be greatly appreciated.

[Einsteinius]

Anyone?

[sayab]

as far as i know everyone has it on friday
my teacher told me to revise enthalphy/calorimetry stuff so neeed to know formulas q=mc(delta)T
there things about amount of substance (unit 1) n=m/mr, pv=nrt, n=c x v etc.
also stuff about alcohols is going to come up so u need to know about the diff test to distinguish beteween eg aldehydes and ketones (fehling's solution etc)
Another thing we were told was there is going to be something about handwarmers ( i guess something to do with exothermic)
i havent done it yet but my teacher told me this.
hope it helps

[byebyebadman]

I think we're going to be tested on acid/base titrations, enthalpy of neutralisation and alcohols.

Looking through past EMPA's, questions seem to be worth one mark. So what sorts of questions do you think we could be asked?

Acid/Base:

Working out the number of moles of a volume of base with known concentration? Knowing that an equal amount of strong base will have been added to an amount of strong acid to reach the end point of a titration?

I can't think of much more? We'll be using an indicator right? So no pH meter, therefore no scope for plotting a titration/graph curve?

Enthalpy of Neutralisation:

Don't know what they could ask?

Alcohols:

Tests for different types of alcohols?

[rss.914]

are you allowed to change a result or change a table from the previous tasks in the empa?

[firefox7451]

(Original post by JamilMCR)
Just wondering if anyone has any tips on how to revise for the chemistry empa (Unit 3) for AQA or if anyone has had the test already? Any help will be greatly appreciated.

Hi,
Do you know what topics to revise for chemistry empa?
I have already done bio.

[Vip3rgt9]

(Original post by rss.914)
are you allowed to change a result or change a table from the previous tasks in the empa?

I don't think anyone can stop you seeing as it wont have been marked and you should get it back when doing the written paper.

Also for calculating enthalpy of neutralisation do you include the masses and moles of both the acid and alkali combined?

[Louhearty]

Teacher also told us to revise biofuels, how they are created and how they are carbon neutral. (Fermentation of sugars) (Hydration of Ethene) Etc etc.

Could also ask us some Nucleophilic Substitution stuff.

Think main point of revision is around alcohols.

[Louhearty]

Definitions are also a biggy.


Hess' law. Enthalpy change of formation. Maybe even le chateliers principle?

[Aqib7]

Does anybody know what the questions in the exam paper are like?

[Yumnaarrhhh]

(Original post by Aqib7)
Does anybody know what the questions in the exam paper are like?

look at 2011/2010 pastpapers on the AQA website, apparently the lay out is similar

[sayab]

Has everybody done it so we can discuss it here??

[b.harrison57]

Ahh I have this test on Monday, so nervous! I reckon it will definitely have the average n=cv and m=nM calculations, we'll have to plot a cooling curve, know what happens when Sodium Hydrogencarbonate is heated. I was thinking there may be a question involving hydrated molecules - working out the emperical formula for Compound-xH20. Naming organic compounds may come up, and alcohols - chemical tests for aldehydes and keytones etc. I'm trying to think of the topics which have been given and how they could relate to our experiment.

[KSmith15]

Hi, my teacher said that for this exam we need to know why a solid acid and solid base react, can anyone help me please?

[Magenta96]

I know what the 2 tasks are about, but which is the first task about? The decomposition one or the neutralisation one?

[Magenta96]

(Original post by b.harrison57)
Ahh I have this test on Monday, so nervous! I reckon it will definitely have the average n=cv and m=nM calculations, we'll have to plot a cooling curve, know what happens when Sodium Hydrogencarbonate is heated. I was thinking there may be a question involving hydrated molecules - working out the emperical formula for Compound-xH20. Naming organic compounds may come up, and alcohols - chemical tests for aldehydes and keytones etc. I'm trying to think of the topics which have been given and how they could relate to our experiment.

in the first task, am I right to say it's just us doing a practical and recording our results? Our teacher kept telling us in task 1 & 2 there are no graphs or questions but then I don't want to end up not revising it, and I end up getting a question.

[Kim Moffatt]

Yes that's right. Only have to record your tables, no questions or calculations, they appear on the written paper

[chemistryempa200]

Can anybody tell me why you had to leave the cruicible to cool in the 1st task? there must be a reason as to why........

[lucasluke]

(Original post by chemistryempa200)
Can anybody tell me why you had to leave the cruicible to cool in the 1st task? there must be a reason as to why........

Safety reasons?

[chemistryempa200]

i doubt it will be for safety reasons, baring in mind you were using tongues anyway.