Peckles Registered User
#1

So I'm studying chemistry for the gamsats next Wed, and slowly resigning myself to the fact that I will never understand chemistry. I'm pulling my hair out with this a particular question which I have a screenshot of, however, I'm unable to post it here. My question is about notation - the multiple answers are in the form of R = R' = R'' = R''' = H etc. My question is this; what the hell are the '=' supposed to mean? Usually it represents a double bond, but how can that be correct for H? Apologies if this is a stupid question, I'm actually losing my mind with this exam and I've never studied chemistry before. Any help would be GREATLY appreciated, thanks guys! Also If anyone knows of any worked examples which are useful to study, please let me know. Freaking out as I have been studying material, khan academy etc only to now see that I cannot relate any of it to GAMSAT questions

hobes Registered User
#2

Sorry I can't post links, but Google:

Chemistry R prime

Hopefully that helps

#3

Yes I remember this question. First off, the '=' is an equals sign in this question, not a double bond.

R, R', R" and all R"' all represent different bonded groups to the carbon atom they are connected to in the diagrams. Eg of a group could be CH3 or even H. However it strictly tells you in the question that R', R" and R"' can be H (among some other groups I can't remember right now) and doesn't say this regarding R so you can assume that R is not H in any of the answers.

I think it tells you that an Aldehyde or a Ketone bonds with an Ester. These are families of organic compounds and once you can recognize them easily you will be flying. They each have a basic structural pattern which you should learn off. Applying this knowledge is key to answering the questions that follow.

Sorry this is a bit vague and I hope it helps. My tip to you would be to prioritise the other science questions and leave the chem until after you the others completed. Relax on the day, and hope for the best.

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