[AL] Lattice enthalpy ~help
A person made the following ermark:"When cmpared woth CaO(s), MgO(s) has a more -ve lattive enthalpy and is therefore more stable from the point of energetics"
Do you agree? Explain. No
唔同element點比較ar[]
打個比喻
2個人跑步,阿A跑到A點就停la,阿B過左A點再跑多10米
阿B好似跑得多過A,但原來2個人起跑果點都唔同,所以其實係唔知邊個跑得遠d[]
[ 本帖最後由 piyopiyo 於 19-11-2008 20:11 編輯 ] 明解了.....
[ 本帖最後由 octopus001 於 19-11-2008 13:08 編輯 ] energy change 唔反映個species 係stable d 定less stable d 咁點睇佢 stable d 定less stable
我前日做功課用左Lattice enthalpy黎搵邊個stable d.....[] Ca2+(g) + O2-(g) --> CaO(s) ΔH < 0 means CaO(s) is energetically more stable than
Lattice energy: used to compare ionic bond strength
Stability: need to consider the IE, EA, etc, therefore, the enthalpy change of formation. 呢題我F.6下學期做過,最近又做過
No
係因為stable or not睇enthalpy change of formation(c.f個element)
當然你要解釋點解上半句岩 enthalpy change of formation of one stuff > other stuff (different chemicals)
then u can say 大d magnitude = more stable??
我地定S.E.C of formation of element in standard state =0 KJ mol^-1
唔通代表左O2 ge "energy" 係一樣於"C(graphite)" ge energy?
我地只能夠用佢比較同一種constituents ge compounds ja bor
e.g. MgCl, MgCl2, MgCl3 Mg2Cl2...
CaO 同MgO 係不能直接比較
回復 8# 的帖子
所以要比較from Ca去CaO 既enthalpy Change同Mg 去MgO既enthalpy change 原帖由 j32738 於 22-11-2008 13:11 發表 http://www4.nakuz.com/bbs/images/common/back.gif
所以要比較from Ca去CaO 既enthalpy Change
同Mg 去MgO既enthalpy change
但係都比較唔到CaO定MgO邊個stable d gor wor[]
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