標題: chem: Mg 的flame test [打印本頁] 作者: 乂...#興乂 時間: 20-7-2009 01:00 標題: chem: Mg 的flame test Na 嘅 flame test 出 yellow
Ca 嘅flame test 出 brick red
Mg 嘅flame test 出 shiney white
但mg 的 e- 照常理會emit radiation in form of light(discrete line) and back to ground state after excitation,出黎嘅colour 應該係某一色(e.g. calcium出brick red),唔應該會係白光。假如係白光,咪即係continous spectrum,即係mg嘅 e-可以去哂所有energy level? 又好似冇可能=.=
一條extra的問題:假如flame test 做得耐,例如係咁燒舊 sodium,會唔會愈燒colour愈唔明顯。假如係,係咪因Na-->NaO 每粒sodium少左兩粒electron to promote,所以少左兩粒electron reemit energy~?作者: Hinton 時間: 10-8-2009 10:43
你第一個問題我未必答到你
因為白光個spectrum係咪超多/continous spectrum
我都唔係好清楚
但第二個問題其實好簡單
你諗返CE
有sodium ions既compund
係flame test 都會出yellow flame
咁Mg 同 MgO 原理一樣姐作者: paladin 時間: 10-11-2011 23:28
white flash of Mg METAL is due to white hot;
note that it is Mg metal, not compounds, Mg compounds give no visible change in flame color;
and no matter you burn sodium metal or sodium compounds, sodium particles are atomized before excitation, so comsumption of sodium metal to compound will not reduce the phenomenon, the same.作者: tomy175 時間: 15-11-2011 20:39
做到flame test既係cation而唔係個element 本身
而Mg 燒有佢有flash係因為佢同air react中放光
Mg ion 做flame test係no visible colour