OCR Chemistry A Exam Thread (Breadth - May 27 2016 and Depth - June 10 2016)

Purifying an organic liquid:
We normally do this after a distillation.
1. Put the distillate of organic liquid into a separating funnel.
2. Add sodium chloride to separate the aqueous layer from the organic layer.
3. add sodium hydrogen carbonate to react an remaining acid.
4. Run organic layer into a conical flask
5. Add a drying agent (such as magnesium sulphate) to remove waters of crystallization.
6. Distilled the remaining liquid to obtain pure product.




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Once again thanks! I've never come across this. Is it the cyclohexane thing?

GOOD LUCK EVERYONE

Is there a way to avoid getting the signs wrong in enthalpy calculations

It's almost time, good luck everyone, make sure you read each question carefully (twice if needed) answer every question and be calm!!
For any last minute queries don't hesitate to ask.

Also do we need to know the practicals on equilibrium?

There was a lot of equilbrium in the breadth so its very unlikely to come up again

I'm really mad at myself bc at the last minute I changed my answer for the last question because I got confused about the secondary carbocation😭😭

I thought that was a good paper. I ****ed up the percentage yield question because I couldn't get anything other than 100.3%, but I was fairly confident on everything else.

what did you get get?
I think it was butanoic acid

I ran out of time so badly I'm really annoyed at myself😩