OCR Chemistry A F325 Equilibria, Energetics and Elements Wed 13 June 2012

so would i get full marks or not?

I'd say 2 or 3 marks, because some things weren't that clear - don't hate me though! Have you done F325 past papers?

I made it up, think about it if you add Na to phenol you'll form phenol and conjugate base (phenoxide). It's a synoptic question.

Is that from an actual paper?
Since when can you make a buffer solution from an alcohol :/ do tell...

Oh I see, aren't buffer solutions produced using a weak acid and it's salt? It'd make more sense if it was benzoic acid

yes and i got full marks for these types of question cause u get a mark for writing the equation second mark for saying moving to left then third mark for moving to right?

Er yeah usually. But if it's worth 5 marks they'd like you to say that the H+ reacts with the alkali and CH3CHOHCOO- reacts with the acid.

phenol is a weak acid and to form the salt you add Na.

yes true can i have more

Which has a more exothermic LE and why?
MgI2 or NaI

MgI because it has a smaller atomic radius and has a greater charge density than NaI therefore more energy is needed to break bonds

Must say that Mg2+ has the smaller ionic radius and greater charge density - not MgI2 as it's a compound. Also Mg2+ has a greater attraction to I- rather than bond breaking.
My advice is to look at the MS more carefully, especially the additional info column.

I wanted to say these but just did short form with key words only but in exam I am going to write those
More please

Mkay, I have to go to bed now - long day lol. Tomorrow?

I'm basically doing similar revision to you, and I hope to finish this week then concentrate on past papers next week damn this unit is hard...

It feels like i'm sitting more of a maths exam, been looking through my notes and it's all calculations except for transition metals, dreading that topic :s

It feels like i'm sitting more of a maths exam, been looking through my notes and it's all calculations except for transition metals, dreading that topic :s

do u want to revise?

Yes me too! i do so badly in the maths questions, the questions can be really weird and confussing and then I don't really know how to go about it and aswer the question...



If you're good at the maths questions you could explain them more if you want

sure like what for example which part in particular ?