2018年8月28日 · Using this website, input the activation energy and temperature and it gives half life. A reasonable half-life is up to the user, but more than 1 day is going to be super slow. Usually assume the transmission coefficient is less than 1 (e.g. 0.5). For example, an upper bound at room temperature is usually less than 25 kcal/mol $\approx$ 105 kJ ...

2019年12月12日 · Room temperature is not among these, so ideally, an exact value must be specified alongside, if relevant, e.g. "the parameter has been determined at r.t. $(\pu{20 °C})$ ". German Wikipedia article presents an observation that in physical chemistry and statistical physics in European region the typical value taken for r.t. is $\pu{20 °C ...

2015年9月21日 · "This reaction requires XYZ activation energy, therefore it cannot happen at room temperature." is a sentence I find often in organic chemistry textbooks. Activation energies are steadily given in textbooks too.

2024年5月1日 · That said, there are higher temperature superconductors, and some do work near room temperature (well, perhaps in Hôtel de Glace, with the caveat at high pressure. For example, $\ce{LaH10}$ , at 170 GPa and -23°C.

2016年11月23日 · Ah, refluxing dichloromethane; i.e. room temperature. You wouldn’t want to put your bare hands in forever, but boiling DCM should be much better for this purpose than boiling water. Also, consult the material safety data sheet and be certain you know what you’re doing before you attempt this!

2015年11月27日 · @Diracology and @Floris provide an in depth exposition of the relationship between critical points and van der Waals constants in their answers to my Physics.SE question Fluids with critical point at ordinary temperature and pressure. Their answers with internet search of van der Waals constant data lead me to start looking at at large ...

2019年4月6日 · The room around a refrigerator is warmed as it receives the heat removed from inside the box. If you leave the door open, heat is merely recycled from the room into the refrigerator, then back into the room. A net room temperature increase would result from the heat of the motor that would be constantly running to move energy around in a circle.

2017年10月15日 · But in doing so, it drains heat from its surroundings and thus stays at room temperature (or close to it), so there is still some fraction of molecules that can evaporate, and they do so, and more heat is transferred from the surroundings, and so …

2019年4月24日 · What is the least dense liquid under normal conditions, room temperature, one atmosphere of pressure, doesn't combust upon contact with air, also wouldn't kill a human just for being in the same ro...

2020年9月21日 · Hence, while you can't change hydrogen into a liquid at room temperature, you can change it into a (supercritical) fluid. Incidentally, there are two established storage technologies for pure hydrogen in vehicles. One involves cooling the hydrogen below its critical temperature and liquifying it.