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Equilibria, Energetics and Elements (F325) - June 2011 Exam.

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I doubt Buffer would come up again, it already came up twice like an essay question, if it comes out it cant be for 7marks or nothing like that,

thats true !

can you quickly explain the concept of feasibility of a reaction in terms of entropy..
when i think i understand it, i find out i dont :frown:

Reply 1541

darkiee

Original post by Ayostunner

thats true !

can you quickly explain the concept of feasibility of a reaction in terms of entropy..
when i think i understand it, i find out i dont :frown:

Basically watch this clips, he teaches good

http://www.youtube.com/user/bradyexplains#p/u/5/PwRdgb0kIQg

^=delta

^G= ^h-t^s

if ^G<0 reaction is feasible,

and That man explains it well as I dont know what part you dont understand

Reply 1542

Ayostunner

Original post by darkiee

Thanks

Reply 1543

darkiee

Original post by Ayostunner

Thanks

No Problemo, you will enjoy his lesson, I hope OCR doesnt mess up and ruin my chance of UNI

Reply 1544

Sereni

Original post by darkiee

LOOL so do i, goodluck AYO, bornhaber or enthalpy change of solution defo is coming, I can bet my house on that. Also essay on Transition metal, lattice eenthlapy or STANDARD ELECTRODE POTENTIAL

Lol like the 20 mark one in the specimen?

Reply 1545

sportycricketer

Original post by darkiee

LOOL so do i, goodluck AYO, bornhaber or enthalpy change of solution defo is coming, I can bet my house on that. Also essay on Transition metal, lattice eenthlapy or STANDARD ELECTRODE POTENTIAL

Buffer are more or less guaranteed to come up cos OCR love them. And what do you mean by the essay on Lattice Enthalpy and Standard Electrode Potential??

(edited 12 years ago)

arghhhhh

Original post by sportycricketer

Buffer are more or less guaranteed to come up cos OCR love them. And what do you mean by the essay on Lattice Enthalpy and Standard Electrode Potential??

The long questions, worth like 7-11 marks where you have to explain yaself well

Reply 1548

darkiee

Original post by Sereni

Lol like the 20 mark one in the specimen?

Yeah Like that very scary

Reply 1549

Killmepls

Early start, hope I don't fall asleep in the exam lol

Reply 1550

raj16

wen do u use a pt electrode in a half cell?

Reply 1551

Flux_Pav

Original post by raj16

wen do u use a pt electrode in a half cell?

when the other half cell is a non-metal

Reply 1552

raj16

Original post by Flux_Pav

when the other half cell is a non-metal

thanks wat about wen the charges r different? like Cu2+ and Fe3+?

Reply 1553

DrDr

Original post by Flux_Pav

when the other half cell is a non-metal

What about an Fe2+/Fe3+ pt half cell joined to a Copper strip/Cu2+ half cell?

Reply 1554

username340050

Original post by raj16

thanks wat about wen the charges r different? like Cu2+ and Fe3+?

For Charges and Non Metals

Pt is used

lets Say Fe2+ --> Fe3+

and

2Br- ---> Br2.

But the Solution contain "Equimolar Amouts of the Product and Reactant"

IOW, The solution should have 1 Mol Br-/Br and a Platinum Catalyst.

Reply 1555

Flux_Pav

Original post by raj16

thanks wat about wen the charges r different? like Cu2+ and Fe3+?

this is an exception because the two metals exist in more than one oxidation state so platinum electrodes used

Reply 1556

haydyb123

Haven't seen a question about calculating buffers yet, you can bet your life there will be one today.

Reply 1557

Flux_Pav

is the rate constat, K, only affected by temperature too? just like Kc?

Reply 1558

Ecstacy.

Zn ---> Zn2+ + 2e (-0.76)
if you increase the concentration of Zn2+, euilibrium shifts to the LHS.
Why does the whole cell potential be lower?

Cu2+ + 2e ---> Cu (+0.34)
increasing Cu2+, it shifts to the RHS
why is the whole cell potential higher?

is the end point of manganese and iron titration from colourless to the first hint of permanent pink?

if someone can help me with that, thank you.