AQA CHEM2 ~ May 23rd 2012 ~ AS Chemistry
Chemistry exam discussion - share revision tips in preparation for GCSE, A Level and other chemistry exams and discuss how they went afterwards.
-
- Reputation:
- Full Member
- Posts: 77
Re: AQA CHEM2 ~ May 23rd 2012 ~ AS ChemistryI'll play the revision game with you lol(Original post by PowerPuff)
ill take that as a no to playing my game.
And id advice getrevising.com then just searching what topic you want notes on
Start off nice and easy lol;
State Le Chatelier's principle and define the term catalyst. -
- Reputation:
- Adored and Respected Member
- Posts: 596
Re: AQA CHEM2 ~ May 23rd 2012 ~ AS ChemistryInstead of saying heat say excess steam or water heated*(Original post by A level Az)
Elimination reaction, concentrated H2SO4, heat?
What changes bromine water colourless?
and presence of a double bond (electron rich area)
Question for you: How will increasing pressure effect rate of a reaction?Last edited by PowerPuff; 22-05-2012 at 01:09. -
- Reputation:
- Adored and Respected Member
- Posts: 596
Re: AQA CHEM2 ~ May 23rd 2012 ~ AS ChemistryPrinciple:(Original post by MathMad)
I'll play the revision game with you lol
Start off nice and easy lol;
State Le Chatelier's principle and define the term catalyst.
A disturbance in a equlibrium system will cause the equlibirum point to move in the direction which counters this disturbance
Catalyst:
Chemical component speeds up a chemical reaction by finding an alternative pathway with a lower activation energy without being use up in the reactant
My question:
Ionic equation for barium chloride with sulphate ions. -
- Reputation:
- Full Member
- Posts: 77
Re: AQA CHEM2 ~ May 23rd 2012 ~ AS ChemistryWell answered(Original post by PowerPuff)
Principle:
A disturbance in a equlibrium system will cause the equlibirum point to move in the direction which counters this disturbance
Catalyst:
Chemical component speeds up a chemical reaction by finding an alternative pathway with a lower activation energy without being use up in the reactant
My question:
Ionic equation for barium chloride with sulphate ions.
And; Ba2+ + SO42- = BaSO4. Sorry I can't write it on here properly. -
- Reputation:
- Adored and Respected Member
- Posts: 596
Re: AQA CHEM2 ~ May 23rd 2012 ~ AS ChemistryWell done sugar,(Original post by MathMad)
Well answered
And; Ba2+ + SO42- = BaSO4. Sorry I can't write it on here properly.
wheres my question?
you answer then give a quesition, then i answer give a quection ect -
- Reputation:
- Full Member
- Posts: 77
Re: AQA CHEM2 ~ May 23rd 2012 ~ AS ChemistryMy question is; explain the trends in electronegativity down group 7.(Original post by PowerPuff)
Principle:
A disturbance in a equlibrium system will cause the equlibirum point to move in the direction which counters this disturbance
Catalyst:
Chemical component speeds up a chemical reaction by finding an alternative pathway with a lower activation energy without being use up in the reactant
-
- Reputation:
- Overlord in Training
- Posts: 2,823
Re: AQA CHEM2 ~ May 23rd 2012 ~ AS Chemistry(Original post by PowerPuff)
Instead of saying heat say excess steam or water heated*
and presence of a double bond (electron rich area)
Question for you: How will increasing pressure effect rate of a reaction?
, thanks.
It increases the rate of a reaction because it increases the amount of particles per unit volume? And only for reactions that involve gases only. -
- Reputation:
- Adored and Respected Member
- Posts: 596
Re: AQA CHEM2 ~ May 23rd 2012 ~ AS ChemistryEletronegativity descrease down group,(Original post by MathMad)
My question is; explain the trends in electronegativity down group 7.
due to atomic size/mr increasing as you go down as a additional inner main energy/eltron shell is being added, increasing sheilding effect therefore outer eletrons are further away and less attracted to possitive nucleus.
yes?
My question: Give the reagent and condition for elimination and nucelophilic substitution reactions in alcohols -
- Reputation:
- Full Member
- Posts: 77
Re: AQA CHEM2 ~ May 23rd 2012 ~ AS ChemistryPerfect(Original post by PowerPuff)
Eletronegativity descrease down group,
due to atomic size/mr increasing as you go down as a additional inner main energy/eltron shell is being added, increasing sheilding effect therefore outer eletrons are further away and less attracted to possitive nucleus.
yes?
My question: Give the reagent and condition for elimination and nucelophilic substitution reactions in alcohols Positive charge of nucleus though but I understand what you mean
Nucleophilic substitution reaction in alcohol; Warm aqueous sodium
Elimination reaction in alcohol; concentrated sulfuric acid, reflux? -
- Reputation:
- Full Member
- Posts: 77
Re: AQA CHEM2 ~ May 23rd 2012 ~ AS ChemistryLol I forget to write my question again(Original post by PowerPuff)
Eletronegativity descrease down group,
due to atomic size/mr increasing as you go down as a additional inner main energy/eltron shell is being added, increasing sheilding effect therefore outer eletrons are further away and less attracted to possitive nucleus.
yes?
My question: Give the reagent and condition for elimination and nucelophilic substitution reactions in alcohols
Ermmm; Tollen's reagent is a type of oxidising agent which can be used to distinguish between aldehydes and ketones.
Describe what you would observe if Tollen's reagent is heated with a separate sample of aldehyde and ketone.Last edited by MathMad; 22-05-2012 at 01:28. -
- Reputation:
- Adored and Respected Member
- Posts: 596
Re: AQA CHEM2 ~ May 23rd 2012 ~ AS ChemistryNo. A topic to revise for ya then?(Original post by MathMad)
Perfect Positive charge of nucleus though but I understand what you mean
Nucleophilic substitution reaction in alcohol; Warm aqueous sodium
Elimination reaction in alcohol; concentrated sulfuric acid, reflux?
N. Sub = Hydroxide ions present as Potasium Hydroxide in aqueous solution, primary alcohol in room temperature
Elimin = Ethanoic Solution, no water present, heated/ high temperature with use of tertiary alcohol -
- Reputation:
- Adored and Respected Member
- Posts: 596
Re: AQA CHEM2 ~ May 23rd 2012 ~ AS ChemistryAldehyde: Silver Mirror (black metalic precipitate within testube)(Original post by MathMad)
Lol I forget to write my question again
Ermmm; Tollen's reagent is a type of oxidising agent which can be used to distinguish between aldehydes and ketones.
Describe what you would observe if Tollen's reagent is heated with a separate sample of aldehyde and ketone.
Ketone: No observable change
Q: Name two advantages of producing ethanol from crude oil? -
- Reputation:
- Full Member
- Posts: 77
Re: AQA CHEM2 ~ May 23rd 2012 ~ AS Chemistrylol yep I need to revise for it tomorrow(Original post by PowerPuff)
No. A topic to revise for ya then?
N. Sub = Hydroxide ions present as Potasium Hydroxide in aqueous solution, primary alcohol in room temperature
Elimin = Ethanoic Solution, no water present, heated/ high temperature with use of tertiary alcohol thanks for the answer.
-
- Reputation:
- Adored and Respected Member
- Posts: 444
(Z) zey are on zee zame zide(Original post by WizKidd)
I don't think remembering German makes it particularly easier LOL
(E) they are enemies I.e both are not on
The same plane as the carbon carbon double bond
And my they I mean the priority groups-
The atoms/molecules with higher Ar/Mr on each side
Of the double bond.
Hope that helps
----
Oh sorry you already got a reply
Silly me :P
This was posted from The Student Room's iPhone/iPad AppLast edited by Hdizzle; 22-05-2012 at 05:30. -
- Reputation:
- Exalted Member
- Posts: 329
Re: AQA CHEM2 ~ May 23rd 2012 ~ AS Chemistryyeh redox for concentrated sulpuric acid and a h-x ( x is a halogen)(Original post by xDesertRose)
Do we have to know these equations anyone?
This was posted from The Student Room's iPhone/iPad App -
- Reputation:
- Exalted Member
- Posts: 325
Best get cracking on then lol its only these equations i find difficult to remember and lose marks on the rest is ok -_-(Original post by cheesecake11)
yeh redox for concentrated sulpuric acid and a h-x ( x is a halogen)
This was posted from The Student Room's iPhone/iPad App
, thanks.
so going to have to do a lot of work today to make up for it! :/
