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Iodine $\ce{I2}$ does not exist in basic solution. It is transformed into a mixture of iodide and iodate, according to the equation $$\ce{3 I2 + 6 OH^- -> 5 I^- + IO3^- + 3 H2O}$$ This reaction is slow if the solution is highly diluted. It does not happen if the iodine solution is neutral or acidic.


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If you resort to $\ce{^1H}$-NMR for an estimation of concentration you should look out for unique signals (here: either belonging to the butenone (A), or the cymene (E)) simple in shape (this prefers a singlet over a triplet), easy to recognize, which do not overlap with signals by the other compound, and still refer to similar nuclei in terms of their ...


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No, the experiment as depicted is basically correct, see my comment below, however, on what is likely understated. Remember ammonia is highly soluble in water, so without Tube 'B', the water in Tube 'C' could backflow. In reality, the volume of Tube 'B' is much larger than depicted to address backflow issues. I would personally replace it with a large heavy ...


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If you want the best estimate from the existing spectra, add up the signal areas from the non-overlapping peaks (so not the signals near 2.8 ppm), add up the expected number of protons for those peaks, and use the formula you have. This will average out some of the noise. If you want to know how many significant digits would be reasonable (less than 4), look ...


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The key here is to look at what excipients (inactive ingredients) are in the capsule you are using. It is usually the case that what's inside the capsule is not the pure active ingredient, but is instead mixed with excipients that e.g. improve the bioavailability of the active ingredient. Certainly, the vitamins D are lipophilic (fat-soluble) substances (and ...


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React carbon-dioxide with hydrogen in the Sabatier process to get methane. 400 °C, high pressure and Nickel catalyst needed. The process is slighly exothermic so it can keep going on its own: $$\ce{CO2} + \ce{4H2} \rightarrow \ce{CH4} + 2\ce{H2O}$$ This process have been proposed to generate fuel on Mars, and used on the ISS to process exhaled carbon-dioxide....


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The gas would become solid, as the gas to solid transition does not have critical temperature, at least for usual orders of temperature. The needed pressure is just a question of the gas temperature. If we can achieve such a pressure is another question.


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After the synthesis, your crude solid acetaminophen contains dark impurities, which have been formed from oxidation of the starting material, 4-aminophenol that carried along during the synthesis (if you have used 4-aminophenol as it is without purification). These impurities are intensely colored dyes of unknown structures with highly conjugated chromophore,...


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