Equilibria, Energetics and Elements (F325) - January 2012 Exam.

72 for an A was the grade boundary for last-years June 2011 paper with the dreaded "Magic Tang" question. This paper was easier than that one so I don't think I will be 72 for an A, maybe around 76?

Anode and Cathode, I'm getting so many different definitions for this. Can anyone simply tell me what the difference between the two are and the reactions that occur at the anode and cathode.

What did you guys for the lattice enthalpy? ~ -2506?

I remember getting something like -2024, :/

ohh , um lets try and solve this. I multiplied the enthalpy change of atmosiation of Na by2 and err something else involving Na by 2.

Anode and Cathode, I'm getting so many different definitions for this. Can anyone simply tell me what the difference between the two are and the reactions that occur at the anode and cathode.

I multiplied one thing by 2, but forgot to multiply the other -____- I've made so many little silly mistakes! -__- Not going to get my A :') bleh, heres to retakes! :L

Please bare in mind im not 100% right. Plus it was only 3 marks? so we'll get atleast 2/3 for working right?

Did you manage to do the final question? why kr2cr2o7 is more sutiable than mn04?

I understand, but i remember that I only multiplied one of the sodium things by 2, not the other. :/ and no i didnt, I had a feeling it would be about the electrochemical values, but I was comparing them with the iron electrode, which didnt make sense, when I think that you had to compare them to the chlorine electrode :/ What did you write about why you cant predict the lattice enthalpy for Na2CO3, and why you cant say which of magnesium sulfide or sodium oxide (?) are more/less exothermic?

i tried to compare the electrodes but the book says that the greater the difference in V the more likely? And Mno4 had the greater difference , totally baffled by that. Um i think i knew what it was but i couldn't put it into words. because Mn was more exothermic than Na but S was more exothermic than O. Heh Its because its impossible to form one mole of an ionic compound from its gaseous ions.

Lol yeah :L I said that Mg is smaller than Na so has more attraction, but O is smaller than the sulfide ion, so O will have a greater attraction to the Na, so this will balance out. I also said that you can't atomise CO3- ions as it isn't in its standard state? I'm hoping thats right! To be honest, I don't mind retaking this unit, I prefer physical chemistry calculations compared to the more organic unit :/

ohh yeah standard states. i think i held my ground pretty well considering i only had 5 days to cover it ;P. I prefer physical chemistry also, lol but i would mind retaking this unit though, same goes with F324. Hope they are both finally dealt with . I'm trying to think what else bugged me.

Lol :L I got 90% in the mock, but I always do worse in the actual thing. Like I said, i don't mind retaking this unit so much, as I like the material and oh, so you've done F324 as well, how is it? I can't/don't want to think of anything else that bugged me, because I will worry otherwise :L

Omg same here! reading these threads make me worry like hell. I try to avoid TSR unless i know i done Ok. i was getting mid A's when i did F325 mocks. I found F324 reasonable, the final question really got to me, How did you find it?

What did you guys for the lattice enthalpy? ~ -2506?

but then again people are gonna make silly mistakes...with workings...equations...and there were a few tricky questions in there. Im not too sure about grade boundaries

What did you guys for the lattice enthalpy? ~ -2506?

How about 74 for an A. i think thats reasonable. what do u say???

Im just wanting low grade boundaries tbh!
I need the UMS mainly