1 / 3

Group IV

Group IV. The Ammonium Carbonate Group Ca 2+ , Sr 2+ , Ba 2+. 目的 學習 第四族 陽離子的分離與確定，精練操作技術與原理應用。. 原理 BaSO 4 非常的不溶，溶解度為 1.1×10 -10 。 CaSO 4 少溶，溶解度為 2.4×10 -5 ， SrSO 4 少溶，溶解度為 3.2×10 -7 。. Note (1) Ba 2+ + CrO 4 2- 會形成 BaCrO 4 黃色 沉澱， 可以證明 Ba 2+ 的 存在。

kiefer
Download Presentation

Group IV

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 IV The Ammonium Carbonate Group Ca2+, Sr2+, Ba2+

  2. 目的 學習第四族陽離子的分離與確定，精練操作技術與原理應用。 原理 BaSO4非常的不溶，溶解度為1.1×10-10。CaSO4少溶，溶解度為2.4×10-5， SrSO4少溶，溶解度為3.2×10-7。 Note (1) Ba2+ + CrO42-會形成BaCrO4黃色沉澱，可以證明Ba2+的存在。 (2) CaC2O4是弱酸的鹽類，可以溶於強酸中，因此要形成CaC2O4沉澱必須在鹼性條件下。 (3) Na2CO3當日現配。

  3. 1滴 6 M NH4Cl 15 M NH3→ base + 5滴 (NH4)2CO3 Group IV: 各3滴 Ca2+, Sr2+, Ba2+, 7滴 NH4+ ∆ 溫水 ppt 6-1 + 6 M HOAc + 3 M NH4C2H3O2 + 10 滴 H2O + K2CrO4 sol 6-1 base + 1 滴 (NH4)CO3 沉澱完全後, +HCl→ acid ppt 6-2 + 6 M HCl + 1 mL H2O + ¼ 刮勺 HNH2SO3 ∆ 10 mins sol 6-2 + 6 M NaOH→ base + 5滴 Na2CO3 Group V ppt 6-3 + 2-4 滴 HNO3, 坩鍋 ∆ 冷卻,+5滴 16 M HNO3 ×2 cold path (stir) BaSO4↓ 沉澱 (黃色) ppt 6-4 + 5- 10 滴 H2O + NH3 → base + 三乙醇胺 +(NH4)SO4 sol 6-4 + 1 mL H2O + 15M NH3 → base + (NH4)2C2O4 SrSO4↓ 沉澱 (白色) CaC2O4↓ 沉澱 (白色) 1. Sr2+ + 2NO3-→ Sr(NO3)2↓ 2. Sr(NO3)2↓→ Sr2+ + 2NO3- 3. Sr2+ + SO4-→ SrSO4↓

More Related