음이온 확인 시험

선택적 화학 반응으로 일반적인 음이온 검출하기

Qualitative Analysis Intermediate (High School) 60 분 ~$10.00

목표

특정 침전·산 분해·산화환원 시험을 이용하여 미지 음이온을 확인한다.

배경

Anion analysis complements cation identification in classical qualitative analysis. Unlike cations, anions do not follow a single systematic separation scheme. Instead, they are identified through a series of specific tests: chloride with silver nitrate, sulfate with barium chloride, carbonate with acid, and so on. Understanding these tests reinforces knowledge of solubility rules and reaction types.

안전 경고

  • AgNO₃ stains skin and clothing permanently
  • Use dilute acids only — concentrated acids can produce toxic gases
  • BaCl₂ is toxic if ingested
  • Dispose of silver waste in designated containers

필수 개인 보호 장비

goggles gloves lab_coat

재료

  • Unknown anion solution (10 mL)
    Prepared by instructor
  • Silver nitrate (0.1M AgNO₃) (10 mL)
    For halide tests
  • Barium chloride (0.1M BaCl₂) (5 mL)
    For sulfate test
  • Dilute HNO₃ (2M) (10 mL)
    Acidification
  • Dilute H₂SO₄ (1M) (5 mL)
    For carbonate test
  • Limewater (Ca(OH)₂ solution) (10 mL)
    CO₂ detection
  • Brown ring test reagent (FeSO₄) (5 mL)
    For nitrate test

장비

Test tubes (8) Dropper pipettes Bunsen burner Delivery tube Test tube rack

실험 절차

1

Carbonate test: Add dilute H₂SO₄ to 2 mL of unknown solution and pass any gas through limewater. A milky appearance confirms CO₃²⁻.

8 분
2

Sulfate test: Add BaCl₂ solution to 2 mL of unknown acidified with HNO₃. A white precipitate insoluble in acid confirms SO₄²⁻.

8 분
3

Chloride test: Add AgNO₃ to 2 mL of unknown acidified with HNO₃. A white curdy precipitate soluble in NH₄OH confirms Cl⁻.

8 분 AgNO₃ stains skin
4

Bromide test: Add AgNO₃ as above. A pale yellow precipitate slightly soluble in NH₄OH confirms Br⁻.

8 분
5

Iodide test: Add AgNO₃ as above. A yellow precipitate insoluble in NH₄OH confirms I⁻.

8 분
6

Nitrate test (brown ring): Layer concentrated H₂SO₄ under a mixture of unknown solution and FeSO₄. A brown ring at the junction confirms NO₃⁻.

10 분 Handle concentrated H₂SO₄ with extreme care
7

Record all observations, precipitate colors, and solubility behavior. Cross-reference results to identify the anion(s) present.

10 분

예상 결과

Each anion produces a characteristic response: carbonates effervesce with acid, sulfates give a white BaSO₄ precipitate, halides give colored AgX precipitates, and nitrates produce a brown ring.

정리

Collect silver-containing waste separately. Neutralize acid waste before disposal. Rinse all glassware thoroughly.

세부 정보

카테고리
Qualitative Analysis
난이도
Intermediate (High School)
소요 시간
60 분
예상 비용
$10.00
단계
7
재료
7

더 많은 실험

탄수화물의 아이오딘-전분 시험 30 min 할로겐에 대한 베이슈타인 시험 25 min 침전에 의한 양이온 확인 90 min 비누 용액으로 경수 시험 40 min 식물 색소의 크로마토그래피 60 min 금속 이온에 대한 붕사 구슬 시험 45 min 미지 물질 확인 도전 75 min 불꽃 발광 분광 분석 60 min pH 지시약 무지개 45 min

Frequently Asked Questions

What is the objective of 음이온 확인 시험?
특정 침전·산 분해·산화환원 시험을 이용하여 미지 음이온을 확인한다.
How difficult is 음이온 확인 시험?
This experiment is rated as Intermediate (High School). It takes approximately 60 minutes to complete.
What safety precautions are needed for 음이온 확인 시험?
Key safety precautions include: AgNO₃ stains skin and clothing permanently; Use dilute acids only — concentrated acids can produce toxic gases; BaCl₂ is toxic if ingested.
What materials are needed for 음이온 확인 시험?
The main materials required are: Unknown anion solution, Silver nitrate (0.1M AgNO₃), Barium chloride (0.1M BaCl₂), Dilute HNO₃ (2M), Dilute H₂SO₄ (1M).
What results should I expect from 음이온 확인 시험?
Each anion produces a characteristic response: carbonates effervesce with acid, sulfates give a white BaSO₄ precipitate, halides give colored AgX precipitates, and nitrates produce a brown ring.