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

Reply 1600

KnuckleheadNinja

am i right in thinking there are only three papers for us to practice with??
june 2010
jan 2011
and a specimen?

Reply 1601

Perky perks

Original post by Flux_Pav

it is the voltage when no current flows

so like the cell potential but what does it actually mean?? :s-smilie:

Reply 1602

asem93

Original post by Perky perks

what is e.m.f??

electron motive force..... so the ability of an electron to readily be lost. The greater emf value the more oxidising ability

Reply 1603

Jtking3000

13

Original post by volvicstar

silly question but how do you work out concentration?

....moles divided by volume

Reply 1604

asem93

Original post by Jtking3000

....moles divided by volume

lol...

Reply 1605

CoffeeStinks

11

Original post by volvicstar

silly question but how do you work out concentration?

n=c x v if v is is dm^3 if it's in cm^3 then divide it be 1000.

(edited 12 years ago)

Reply 1606

Flux_Pav

Original post by Perky perks

so like the cell potential but what does it actually mean?? :s-smilie:

tbh i don't know the deeper understanding - i'm just memorizing definitions LOL it works for me

Reply 1607

Perky perks

Original post by asem93

electron motive force..... so the ability of an electron to readily be lost. The greater emf value the more oxidising ability

Original post by Flux_Pav

tbh i don't know the deeper understanding - i'm just memorizing definitions LOL it works for me

Thanks guys :smile:

Reply 1608

123trident

actually, I'm a bit confused on free enrgy feasiblity. Can someone go throug all the options explaining them, please?

Reply 1609

sportycricketer

How does concentration of one solution in a half cell affect the Electrode Potential? How do you if it will be higher or lower?!

Reply 1610

HappyEverLaughter

Original post by sportycricketer

How does concentration of one solution in a half cell affect the Electrode Potential? How do you if it will be higher or lower?!

You use le Chatelier's principle...For example if you increase conc of Cu2+ in Cu2+ + 2 e- =Cu equilibrium moves to the right to minimise change so electrons are removed from the equilibrium causing electrode potential to become less negative (higher).

Reply 1611

Wilzyy

13

Original post by sportycricketer

How does concentration of one solution in a half cell affect the Electrode Potential? How do you if it will be higher or lower?!

If the concentration is different, e.g. not standard conditions, then the Electrode Potential will be different from the Standard value given in the table.
If its lower or higher depends on which half cell (Oxidising agent or reducing agent) has had its concentration changed.

I believe.

Reply 1612

2141

How do you calculate lattice enthalpy using enthalpy changes of solution and hydration ???

Reply 1613

asem93

Original post by 2141

How do you calculate lattice enthalpy using enthalpy changes of solution and hydration ???

you have to use the other form of Born Haber cycle...

Solution + LE = Hydration

Then you rearrange accordingly...... I think anyway (maybe wrong, this is from memory)

Reply 1614

sportycricketer

Original post by HappyEverLaughter

You use le Chatelier's principle...For example if you increase conc of Cu2+ in Cu2+ + 2 e- =Cu equilibrium moves to the right to minimise change so electrons are removed from the equilibrium causing electrode potential to become less negative (higher).