username3835832
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http://pmt.physicsandmathstutor.com/...t-B/Arenes.pdf

I don't get 6a and 6b.

for 6a, I thought can I put 2,4,6-trinitrophenol as that can be produced using conc. HNO3, but in this question they mention dilute HNO3

for 6b this is the markscheme
Mr phenol (C6H6O) = 94.0 (1) Mr 4-nitrophenol (C6H5NO3 ) = 139.0 (1) expected mass/moles of nitrophenol from 100 g = 148 g/1.06 mol (or ecf from wrong Mrs) (1) at 27% yield gives 40 / 39.9 (g) (or ecf) (1) 4 last mark is for 0.27 × expected mass to 2 or 3 sf
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Pigster
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6a the ease of nitration of phenol vs benzene is on the new OCR A spec. as is the difference in the reaction conditions.

6b that's an AS calculation on a Y13 reaction. Why hard?
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username3835832
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(Original post by Pigster)
6a the ease of nitration of phenol vs benzene is on the new OCR A spec. as is the difference in the reaction conditions.

6b that's an AS calculation on a Y13 reaction. Why hard?
6a. I get that but I was wondering if I draw phenol with 3 NO2 on it on positions 2,4,6 would it be correct? I have checked the markscheme but there's not drawing of the molecule on there.

6b. I don't get it whenever a yield is mentioned in the question, and when looking at the markscheme didn't help.
If you can shed some light
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username3835832
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??? Pigster charco
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Pigster
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(Original post by chemquestion)
6a. I get that but I was wondering if I draw phenol with 3 NO2 on it on positions 2,4,6 would it be correct? I have checked the markscheme but there's not drawing of the molecule on there.

6b. I don't get it whenever a yield is mentioned in the question, and when looking at the markscheme didn't help.
If you can shed some light
6a, the Q gives 2 and 4 nitrophenol as possible answers and asks you for another. The Q checks whether you think 6-nitrophenol is possible. But, that is just 2- again. The only one left (that is mononitrated) is 3- (even if that is unlikely).

The MS says "Correct structure of 3-nitrophenol or any multiple nitrated phenol" Why would you ask whether 2,4,6-tri is allowable?

To calculate a yield, you compare (divide) what mass is actually made by how much could have been made (doing a normal molar calc.) and then multiply by 100.
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