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Answers Forum overview -> Basics Chemie message lilyfee Joined: 12/10/2011 Beitrge: 170 Location: Vienna Posted: 27 December 2011 17:45 Title: why is NaCl in aqueous solutions ions and sucrose
My question: Halli-Hallo! In my book it's about electrolytic properties of solutions. As Ex NaCl and sucrose is called. Therefore, diethyl ether NaCl is indeed a good conductor because diethyl ether it forms in aqueous solutions ions, sucrose, however, this does not appear. But I'm not one, not WHY. In the book, this is just that sucrose a molecular compound and neutralist as such, but that's also NaCl or? I mean, NaCl is when viewed as a whole, too neutral, only if you into its components (ie Na + and Cl-divides it) - as it happened when it in water lst - they are just loaded .. but the Schmee should just work but also with sucrose or not? or how can I tell if a compound is ionic (such as NaCl) or not (sucrose)? lg Lg lily lily My ideas: magician4 Moderator Joined: diethyl ether 05/10/2009 Beitrge: 8282 Location: Hamburg Posted: 27 December 2011 19:01 Title: Quote: I mean, NaCl is when you look at it as a whole, too neutral, only when it (ie, Na + and Cl-divided into its components) - as it happened when it l in water st - they are just loaded .. (...) this is exactly the - again quite verstaendlche - error-even if you do at school permanently as "NaCl" as hinpinselt: one which outwardly neutral particles (as plus and minus itself outwardly indeed cancel) there are not usually sodium chloride in normal conditions forms an ion lattice http://de.wikipedia.org/w/index.php?title=Datei:NaCl_polyhedra.png&filetimestamp=20080407140702 ... and in this hanging sodium, chlorine already in ionized form around: the whole is of Na + and Cl - built units, the particles are thus already ionized, and wait pratktisch only to be hydrolyzed to it ([NaCl] 1 you findes only in the gas phase, diethyl ether and there you can then worthy of debate over it whether Na + Cl - ion pairs or covalent Na-Cl ... but to force something you have to put in geschaeft more than 1465C: the feature of this highly energy particles has thus with the property habitual cooking salt at room temperature practically nothing more to do) Quote: .. but the Schmee should just work but also with sucrose or not? no, just not that of sugar crystal diethyl ether does not consist just of oppositely charged ions, but from zuckermolekuelen, among which there are ("intermolecular") are mainly held together by wasserstoffbruecken interactions, and in itself ("intramolecular") each by covalent bonds -> there are neither ionic structures already prefigured, nor by the screen resolution in water such "provoked" Quote: and how can I tell if a connection forms ions (as NaCl) or not (sucrose)? when we talk about ion formation at the screen resolution in water, and do not expect already anyway prefabricated ionic structures (white when NaCl) to the appropriate pKb or pKa values -> you need to investigate the substances that you'd like judge to determine whether this (relevant) acidic (or basic) sub-structures include ["relevant" in the reference system water means: pK / pK B> ~ 10, bigger values (for example alcohols: pK a ~ 16) are considered vernachlaesisgbar (precisely because they are no longer relevant dissociate opposite the self-dissociation of the water), ie for the practice as "not available" to treat] this provides for the anfaenger diethyl ether however, as a rule insuperable obstacles: what will make you know whether trinitrophenol is already diethyl ether relevant acidic (it is: pKa 00:29) , or diphenylamine still relevant basic (it is not: pKb 12.22) or as the undoubted CH acidity would be to judge of acetylacetone now (just grade is still relevant: pKa ~ 9) ... of which you can not make a "beginner" have pale shimmer. -> Are you still at the beginning nothing other choice than abzupruefen diethyl ether with the helpful diethyl ether instrument structures "elektronegativiatestdifferenz larger than ~ 1.7" diethyl ether with single (sub-) whether there could be an ion-binding (Check consequently whether anyway ion present) ... and ... for more complicated things (acetic acid, sugar: therefore diethyl ether check whether from covalent substructures in a relevant scope ionic structures arise when disolve) to take the first learning to knowledgeable how things because each are (acetic acid: yes, sugar: no) : to analyze such things as in my above examples is typically applicable over the school level also greeting ingo ________

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