Aqa chem 4/ chem 5 june 2016 thread

guys would I lose a mark for putting 1-chloroethanoyl chloride?

I wrote the same thing - such a stupid mistake

Was a tough paper, but I can't see the AQA doing much - the questions about lidocaine/polymers for stitches etc were how science works questions that required thinking outside of the box, they've been pretty on point with the HSW stuff in the past couple of years.

That's not to say that the AQA don't realise when they've went off the beaten track - a similar thing happened with the controversial June 2012 CHEM5 paper, there was an outrage including newspaper coverage on it and the AQA lowered the grade boundaries considerably (79 for A* and 71 for an A).

What was the answer?

Hi thank you for doing this! if possible could you add in the marks for the questions so i can estimate how badly i did.. also i dont remember a question about how to distinguish between enantiomers?? Did i miss this??

Currently revising Chem5 after that atrocious chem4

How much do we need to know about reversible and irreversible cells? Do we need to know the half equations for examples etc or do we only have to know that the reaction can be reversed in rechargeable cells?

Pretty sure we don't need to know the equations, just how to work out the reactions if they are given in a table.

Although, considering the last paper, who knows? They might even bung that in there too -_-

Hey guys, for unit 5 born haber cycles I'm just unsure on one thing. Say for example say you're asked to draw the cycle for NaCl can you do the atomisation for Na then the atomisation for 1/2Cl2 then do the first IE or does it have to be Atomisation Na then IE then atomisation 1/2Cl2? Thanks

the ethanal and ethanol reaction was nucleophillic addition elimination ?

No, just nucleophilic addition.

What was being eliminated? We ended up with a diol I seem to remember.

EDIT: Scrap that, it was hemiacetal, which is a hydroxy ether, but still nucleophilic addition.

wasn't one of the hydrogens lost on the oxygen ? because youv'e gone from an alcohol to an ether ?

Yes, but this isn't a leaving group, this is only being picked up by the leftover base (i.e. O+) and donating an electron pair to O+.

No C=O double bond was re-formed by kicking out a leaving group: O:- accepted a proton to form the hydroxyl group.

Was a tough paper, but I can't see the AQA doing much - the questions about lidocaine/polymers for stitches etc were how science works questions that required thinking outside of the box, they've been pretty on point with the HSW stuff in the past couple of years..