Lattice Energy
 lattice energy | |
|---|---|
| Bayanai | |
| Ƙaramin ɓangare na | Makamashi |
Facet of (en)  |
crystal structure (en) |
A cikin ilimin sanin sinadarai, makamashin lattice shine canjin kuzari bayan samuwar mole guda ɗaya na fili na ionic crystalline daga abubuwan da ke cikinsa, waɗanda aka ɗauka suna cikin yanayin gas. Ma'auni ne na rundunonin haɗin kai waɗanda ke ɗaure daskararrun ionic. Girman makamashin lattice yana haɗe da wasu kaddarorin jiki da yawa waɗanda suka haɗa da narkewa, taurin kai, da rashin ƙarfi. Tun da gabaɗaya ba za a iya auna shi kai tsaye ba, yawancin kuzarin da aka yi amfani da shi ana cire shi daga bayanan gwaji ta hanyar zagayowar Haihuwa-Haber.[1]h
Theoretical treatments
[gyara sashe | gyara masomin]Makamashin Lattice da Makamashin Enthalpy
[gyara sashe | gyara masomin]Tunanin makamashin lattice an fara amfani da shi ne ga samuwar mahadi tare da sifofi kamar rocksalt (NaCl) da sphalerite (ZnS) inda ions ke mamaye rukunin yanar gizo na simmetry na crystal. A cikin yanayin NaCl, makamashin lattice shine canjin makamashi na amsawa
Na+ (g) + Cl− (g) → NaCl (s)
wanda ya kai -786 kJ/mol.[2]
Wasu litattafan ilmin sinadarai[3] da kuma Littafin Jagoran Chemistry da Physics na CRC da aka fi amfani da shi[4] suna ayyana makamashin lattice tare da kishiyar alamar, watau a matsayin makamashin da ake buƙata don juyar da kristal zuwa ions na iskar gas mara iyaka a cikin sarari, tsari na endothermic. Bayan wannan al'ada, makamashin lattice na NaCl zai kasance +786 kJ/mol. Ana amfani da duk ƙa'idodin alamomin biyu ko'ina.
Dangantakar da ke tsakanin makamashin lattice da lattice enthalpy a matsi P an bayar da ita ta wannan ma'auni mai zuwa:
,
inda ΔUlattice shine makamashin lettice (watau canjin makamashi na cikin gida), ΔHlattice shine enthalpy na lattice, da ΔVm Tun da ƙarar ƙaƙƙarfan ƙaƙƙarfan ya yi ƙanƙanta da na iskar gas, ΔVm<0. Samar da lattice crystal daga ions a cikin sarari dole ne ya rage kuzarin cikin gida saboda ƙaƙƙarfan ƙarfin da abin ya shafa, don haka ΔUlattice <0. Kalmar -PΔVm yana da inganci amma yana da ɗan ƙarami a ƙananan matsi, don haka ƙimar enthalpy ɗin lattice shima mara kyau ne (kuma exothermic).
Ka,idojin Kula
[gyara sashe | gyara masomin]Ƙarfin wutar lantarki na fili na ionic ya dogara da ƙarfi akan cajin ions waɗanda suka ƙunshi ƙarfi, waɗanda dole ne su jawo hankalin juna ko tunkuɗe juna ta hanyar Dokar Coulomb. Fiye da wayo, dangi da cikakkun girman ions suna tasiri ΔHlattice. Har ila yau, sojojin tarwatsawa na London suna wanzu tsakanin ions kuma suna ba da gudummawa ga makamashin lattice ta hanyar tasirin polarization. Don mahadi na ionic da aka yi da cations na kwayoyin halitta da/ko anions, ana iya samun ma'amalar ion-dipole da dipole-dipole idan ko dai kwayoyin suna da lokacin dipole na kwayoyin halitta. Jiyya na ka'idar da aka bayyana a ƙasa an mayar da hankali ne akan mahadi da aka yi da cations na atomic da anions, da kuma sakaci da gudummawar da ake bayarwa ga makamashin ciki na lattice daga girgizar lattice mai thermalized.
Manazarta
[gyara sashe | gyara masomin]- ↑ Atkins; et al. (2010). Shriver and Atkins' Inorganic Chemistry (Fifth ed.). New York: W. H. Freeman and Company. ISBN 978-1-4292-1820-7.
- ↑ David Arthur Johnson, Metals and Chemical Change, Open University, Royal Society of Chemistry, 2002,ISBN 0-85404-665-8
- ↑ Zumdahl, Steven S. (1997). Chemistry (4th ed.). Boston: Houghton Mifflin. pp. 357–358. ISBN 978-0-669-41794-4.
- ↑ Haynes, William M.; Lide, David R.; Bruno, Thomas J. (2017). CRC handbook of chemistry and physics : a ready-reference book of chemical and physical data. Boca Raton, FL: CRC Press, Taylor & Francis Group. pp. 12–22 to 12–34. ISBN 9781498754293.