Someone please help me I have been stuck on it for hours.
Answer: FIRST CHECK THE ANSWER ON THE ANSWER LINE IF answer = 1.35 (g) award 3 marks IF answer = 0.54 (g) award 2 marks (no scale-up) IF answer = 0.216 (g) award 2 marks (incorrect scale-up) n(compound D) = 1.73/346 = 0.00500 mol n(1,3-diaminobenzene) required = 100/40 x 0.005 = 0.0125 mol Molar mass of 1,3-diaminobenzene = 108 (g mol–1) AND Mass of 1,3-diaminobenzene = (108)(0.0125) = 1.35 g
Someone please help me I have been stuck on it for hours.
Answer: FIRST CHECK THE ANSWER ON THE ANSWER LINE IF answer = 1.35 (g) award 3 marks IF answer = 0.54 (g) award 2 marks (no scale-up) IF answer = 0.216 (g) award 2 marks (incorrect scale-up) n(compound D) = 1.73/346 = 0.00500 mol n(1,3-diaminobenzene) required = 100/40 x 0.005 = 0.0125 mol Molar mass of 1,3-diaminobenzene = 108 (g mol–1) AND Mass of 1,3-diaminobenzene = (108)(0.0125) = 1.35 g
moles of D = mass/Mr = 1.73/346 = 0.005 mol
This represents 40%, therefore 100% would be 0.005 x 100/40 = 0.0125 mol
Mr of reactant, 1,3-diaminobenzene, C6H8N2 = 108
Hence mass of reactant needed = 0.0125 x 108 = 1.35g
That's a strange question! I know lots of people who are "good" at chemistry.
You are told in the question that the actual percentage yield is 40%, i.e. 40/100
and
percentage yield = actual yield/theoretical yield
So rearranging:
theoretical yield = actual yield/percentage yield = 1.73/0.4 g
Because I want to tag them this question I asked before: Calculate the mass of phenylamine that was produced from the 3.69 g of nitrobenzene in this experiment. Give your answer to three significant figures. Mr : nitrobenzene,123; phenylamine, 93.1
IN QUESTION: Purification gave a 72.1% yield of phenylamine.
''purification gave 72.1% yield of phenylamine''
Does this 72.1 also mean the actual yield that is formed? same as the question I asked at the beginning of this thread?
Because I want to tag them this question I asked before: Calculate the mass of phenylamine that was produced from the 3.69 g of nitrobenzene in this experiment. Give your answer to three significant figures. Mr : nitrobenzene,123; phenylamine, 93.1
IN QUESTION: Purification gave a 72.1% yield of phenylamine.
''purification gave 72.1% yield of phenylamine''
Does this 72.1 also mean the actual yield that is formed? same as the question I asked at the beginning of this thread?
Yes, if the yield is 72.1% it means that you get 72.1/100 of the theoretically possible amount produced.
In a perfect world we would always get 100% of the amount expected, but in the real world with side-reactions and losses due to work-up we often get much less.
Tag "Pigster" - he's a grumpy old bugger, but he'll get the job done
Yes, if the yield is 72.1% it means that you get 72.1/100 of the theoretically possible amount produced.
In a perfect world we would always get 100% of the amount expected, but in the real world with side-reactions and losses due to work-up we often get much less.
Tag "Pigster" - he's a grumpy old bugger, but he'll get the job done
Oh I get that now, but why does it say in the markscheme 100/40? I get 40/100 but not 100/40?