# Tag Info

## New answers tagged physical-chemistry

2

If we vary conditions (temperature/pressure), such that an FCC-BCC phase transition occurred, how would we know the BCC lattice formed? In this paper Zhang & Chen used Möbius pair-potentials to model NaCl phase transitions in an MD simulation, so I am not sure how relevant it is to your question, but they use several indicators of the FCC-BCC ...

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Are isothermal free expansion and adiabatic free expansion different? No. They are the same. Your mistake is in thinking that $PV^\gamma = \text{constant}$ applies to a free expansion. That expression is for a reversible (i.e., isentropic) adiabatic process. A gas that has undergone a free expansion has more entropy after the expansion is complete than ...

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You can not classify free expansions into any of those categories as free expansion is not a reversible process and hence the intermediate states are not well defined. The equations are not working because they find the area under the p-v graph but here no such graph can be made.

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Note that the instructions do not claim that the volume of water is changing measurably over the course of the procedure. The volume of water is not changing noticeably. What this procedure allows one to observe is the fact that a salt+water solution has less volume than the total volume of its ingredients. Rather than a demonstration of water changing ...

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Neutrons and protons are hadrons and are identified as an isotopic spin 1/2 hadron called baryon. There are many hadrons, pions, kaons, detas, etc , and one of the quantum numbers that separates them is the baryon number. Protons and neutrons each have baryon number 1. Thus a neutron turning into a proton does not change the baryon number. Isobaric means ...

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Exact mechanism varies with material, simple materials (non-organic) are easier to analyze. Simplest answer is if you bring them together they will join, provided size is small. For example in Cold Welding less than 10 nm wire is rejoined just by contact. The exact mechanics depends on what kind of Intermolecular force is in play. According to Grove Karl ...

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Densest material on Earth is probably Osmium at 22.59 g/cm3 What the densest material at the Earth's core may be I do not know - probably still Osmium unless some other element forms a higher density allotrope under the pressure

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The lattice energies of ionic compounds are relatively large. The lattice energy of NaCl, for example, is 787.3 kJ/mol , which is only slightly less than the energy given off when natural gas burns. The bond between ions of opposite charge is strongest when the ions are small. For example, an HO–H bond of a water molecule (H–O–H) has 493.4 kJ/mol of ...

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So I found some information in the Chemistry stackexchange that suggests that the correct order is: covalent > ionic > metallic > VDW The answer is provided here. However, it still doesn't make sense to me because I've looked up the values for these bond types and clearly the ionic bond in NaCl is strong than the covalent bond in water between hydrogen and ...

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VSD's work because a portion of the VSD molecule contains a chromophore, that is, a molecular structure that is responsible for absorbing light at one or more particular wavelengths. Absorption of light is entirely a function of the electronic structure of the chromophore. That is, light at a particular wavelength is absorbed by the molecule because the ...

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