1 / 4

Group V

Group V. The Soluble Group N a 2+ , K + , Mg 2+ ,NH 4 +. 目的 學習 第五族 陽離子的分離與確定，精練操作技術與原理應用。. 原理 Mg 2+ + 2OH - → Mg(OH) 2 (s) ↓ 2K + + Na + + Co(NO 2 ) 6 → K 2 NaCo(NO 2 ) 6 ↓ Na + + Mg 2+ + 3UO 2 2+ + 9Co(NO 2 ) 6 +9H 2 O → NaMg (UO 2 ) 3 (C 2 H 3 O 2 ) 9 ． 9H 2 O ↓. Note

hedva
Download Presentation

Group V

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Group V The Soluble Group Na2+, K+, Mg2+,NH4+

  2. 目的 學習第五族陽離子的分離與確定，精練操作技術與原理應用。 原理 Mg2+ + 2OH-→ Mg(OH)2(s) ↓ 2K+ + Na+ + Co(NO2)6→ K2NaCo(NO2)6↓ Na+ + Mg2+ + 3UO22+ + 9Co(NO2)6 +9H2O →NaMg(UO2)3(C2H3O2)9．9H2O ↓ Note (1) MgNH4PO4形成很緩慢，若沉澱物1 分鐘內沒有形成，加熱到沸騰，冷卻靜置，如果沒有沉澱物代表沒有Mg2+的存在。 (2) 磷酸鹽和其它金屬(除了鎂)在這個步驟也會沉澱，因此用S.O試劑(染料)，證明 鎂存在。Mg2+加OH-會形成不溶的Mg(OH)2和S.O試劑結合，會得到藍色的絨毛沉澱。 (3) NH4+會形成黃色沉澱物(NH4)2NaCo(NO2)6，會影響Na+和K+的觀察，必須蒸發完全移除NH4+ 。 (4) Na3Co(NO2)6當日現配。

  3. Group V: 2滴 Mg2+, 2滴 NH4+, 4滴 Na+, 4滴 K+ Group V Mg (base by NaOH) + 1滴 6 M NH4Cl + 2-4 滴 Na2HPO4 靜置 K + 1滴 6 M HOAc + 少量 NaNO3(s) ∆ +1滴 Na3Co(NO2)6 Na + 6滴 醋酸鈾醯鎂 靜置 NaMg(UO2)3(C2H3O2)9．9H2O ↓ 沉澱 (淺綠色) Na+ + Mg2+ + 3UO22+ + 9Co(NO2)6 +9H2O →NaMg(UO2)3(C2H3O2)9．9H2O ↓ ppt 溶於 6 M HCl + 1 滴 S.O 試劑 + NaOH → base K2NaCo(NO2)6↓ 沉澱 (黃色) 2K+ + Na+ + Co(NO2)6→ K2NaCo(NO2)6↓ Mg(OH)2↓ 沉澱 (藍色) 1. Mg2+ + NH4+ + PO4- + 6H2O → MgNH4PO4．6H2O ↓ 2. MgNH4PO4．6H2O ↓ + 2H+→Mg2+ + NH4+ +H2PO4- + 6H2O 3. Mg2+ + 2OH-→ Mg(OH)2(s) ↓

  4. Ca2+ Sr2+ K+ Na+ Mg2+ Ba2+

More Related