OCR A-level Chemistry A Paper 2 - 16th June 2025 [Exam Chat]

You do not need to notice a certain peak. You just need to state what a peak could be and state what the relevant fragment ion is. There is normally like a variety of peaks you could talk about in the mark scheme. I think i mentioned two the obvious one being the RFM of the molecule and the peak are 43 m/z i think.

maybe, thatd make sense bcz not everyone is going to notice every large peak in mass spec, whereas in nmr u have to talk about every single peak. either way each structure contradicts the information we were given, if u picked CH3CH2COOCH(CH3)2 u were contradicting the 71 peak. if u picked CH(CH3)2COOCH2CH3 u were contradicting the NMR and the 88 peak.

Do you think they might accept both structures? Becuase in some nmr questions it gives a few different structures you could choose from?

Do you think they might accept both structures? Becuase in some nmr questions the mark scheme gives a few different structures you could choose from?

Yeah you’ll probably only lose a mark at most

probably! both structures can apply to the data in someway. although shifting is a thing in nmr i dont think ive ever seen it shift HUGELY (which it wouldve had to do to fit the structure that forms the 71 ion)

But did the other structure-(ch3)2chcooch2ch3- not contradict the nmr? ( with the different splitting patterns etc.?)

I honestly don’t remember and even if it did as long as you wrote down all your observations and got a structure that was mostly correct you’ll be fine. I think I just looked at the nmr evidence and based my answer off that.

does anyone remeber the multipl choice on global warming? What was the question again?

does anyone remeber the multipl choice on global warming? What was the question again?

which of these things doesn't involve infrared radiation? (I forgot most of the options but I remember global warming was one of them)

does anyone remember for the 6 mark synthesis question if we had to include mechanisms because i didnt

does anyone remember for the 6 mark synthesis question if we had to include mechanisms because i didnt

Guys was the density of the organic liquid lower or higher than water

did anyone get a diol for nmr lmao