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If there is no further clarification in the specification of the 10% (like 10vol% or 10mol%), then this should indicate a mass fraction. Thus, 10% of the mass of the solution is supposed to be $\ce{KOH}$, so you would dissolve 10 g in 90 g ethanol to get the desired solution. I don't know the precise solubility of $\ce{KOH}$ in ethanol but I assume that, if ...


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Silanol activity is perhaps an informal term which is quite frequently used in the chromatographic literature to explain the poor band shape of primary amines. Other amines show this too but to a lesser extent. That is why you will not find a formal textbook definition of silanol activity. One might also see the term silanophilic interactions used ...


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The tiny scratches on the plastic surface reflect and diffract light in different directions, so edges of objects behind the plastic become distorted, and the clear areas of the plastic are less clear. There are several ways to make the plastic more transparent. Use a finer grit sandpaper - really really fine: 1500 grit or finer, if you can get it. Plastic ...


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As you surmise, quantum mechanics was developed to help explain observations such as that periodicity, spectral lines and the photoelectric effect. However, the solution of the Schrödinger equation is difficult, and not complete beyond hydrogen. For example Wikipedia states, "Unlike for hydrogen, a closed-form solution to the Schrödinger equation for ...


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In short, $\ce{HNO3}$ is an oxidizing acid, so the destruction of the oxide layer competes with formation of new oxide. Something like this: $\ce{Al2O3 + 6H+ -> 2Al^3+ + 3H2O}$ $\ce{2Al + 2Al^3+ + 6NO3- -> 2Al2O3 + 6NO2}$ (<-- maybe incorrect) From Wikipedia: Although chromium (Cr), iron (Fe), and aluminium (Al) readily dissolve in dilute nitric ...


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The reaction of metallic iron powder with sulfuric acid solution is rather slow. But it produces at least some Hydrogen bubbles that are adsorbed against the iron powder. This may be sufficient for maintaining the iron powder at the surface of the solution.


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I think the reason for inverting the the round flask is to capture sunlight very efficiently. A round bottomed flask filled with a fluid is like a ball lens. Sun rays can be considered parallel and see how they focus. If light is coming from all directions, every part will be illuminated well as the Sun moves. See ball lenses here ball lenses The clue comes ...


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In the language of chemistry,in situ means The reaction mixture.Here,in case of HNO2,it is too unstable.Here,if we see the reaction, HNO2→HNO3+NO+H2O The oxidation no of central atom N: in HNO2-+3 in HNO3-+5 (oxidation,as oxidation no increased) in NO-+2(reduction,as oxidation no decreased) If we observe,we can see that,here at the same time, the oxidation ...


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They were hitting the same spot in the sense they landed on an area that was predicted by the spread of the beam. They weren't all traveling exactly the same path. This randomness allowed some of them to bounce from atom nuclei.


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The polarizability of molecules determines how a molecule interacts with other molecules (intermolecular interactions and chemical reactions), how it interacts with electromagnetic radiation (optical properties), and how it interacts with electrical fields (electrical properties). Thus, there are multiple ways to compare the polarizability of two molecules ...


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I agree with M. Farooq, a test that might work is cutting small pieces of thermal paper and placing them in a tube with grain alcohol or a facsimile, and allowing them to soak for a few hours, then send the sample to a lab and ask them to test for bisphenol A/S. If you can, it's just better to ask the company.


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