람베르트-베어 법칙 검증

흡광도와 농도의 선형 관계 실증하기

Colorimetry Intermediate (High School) 60 분 ~$12.00

목표

다양한 농도의 CuSO₄ 용액의 흡광도를 측정하여 검량선을 작성하고 람베르트-베어 법칙을 검증한다.

배경

The Beer-Lambert law states that absorbance is directly proportional to both the concentration of the absorbing species and the path length of the sample (A = εbc). By preparing a series of standard solutions of known concentration and measuring their absorbance at a fixed wavelength, students construct a calibration curve. This curve can then be used to determine the concentration of unknown samples — a technique fundamental to analytical chemistry.

안전 경고

  • CuSO₄ is an irritant — avoid skin contact
  • Do not pipette by mouth
  • Wipe cuvettes with lint-free tissue before measurements
  • Dispose of CuSO₄ solutions in inorganic waste

필수 개인 보호 장비

goggles lab_coat

재료

  • Copper sulfate (CuSO₄·5H₂O) (10 g)
    For stock solution
  • Distilled water (500 mL)
    Solvent
  • Unknown CuSO₄ solution (50 mL)
    Prepared by instructor

장비

Colorimeter or spectrophotometer Cuvettes (matched pair) Volumetric flasks (100 mL, 6 total) Pipettes (10 mL, 25 mL) Pipette filler Graph paper or computer

실험 절차

1

Prepare a 0.5M stock solution by dissolving 12.5 g CuSO₄·5H₂O in distilled water and making up to 100 mL.

5 분
2

Prepare standard solutions by dilution: 0.05, 0.1, 0.2, 0.3, 0.4, and 0.5 M. Label each flask clearly.

10 분
3

Set the colorimeter to 635 nm (red filter) — the maximum absorbance wavelength for blue CuSO₄ solutions.

3 분
4

Zero the instrument using a cuvette of distilled water (blank). Ensure the cuvette is clean and properly oriented.

2 분
5

Measure and record the absorbance of each standard solution, starting from the most dilute. Rinse the cuvette between samples.

15 분
6

Measure the absorbance of the unknown solution.

5 분
7

Plot absorbance (y-axis) vs. concentration (x-axis). Draw the best-fit line and determine the unknown concentration from the graph.

20 분

예상 결과

The plot should show a linear relationship (straight line through the origin) for the standard solutions. The unknown concentration is read from the x-axis at the corresponding absorbance on the calibration curve.

정리

Pour CuSO₄ solutions into the inorganic waste container. Rinse all volumetric flasks and cuvettes with distilled water.

세부 정보

카테고리
Colorimetry
난이도
Intermediate (High School)
소요 시간
60 분
예상 비용
$12.00
단계
7
재료
3

더 많은 실험

분광광도법으로 아스피린 정량 75 min 분광광도법으로 식품 색소 분석 60 min 혼합물의 분광광도법 분석 75 min 인산염의 비색 정량 90 min 포도당의 비색 정량 60 min 비색 단백질 정량(브래드퍼드법) 60 min 물 속 철 함량 결정 75 min

Frequently Asked Questions

What is the objective of 람베르트-베어 법칙 검증?
다양한 농도의 CuSO₄ 용액의 흡광도를 측정하여 검량선을 작성하고 람베르트-베어 법칙을 검증한다.
How difficult is 람베르트-베어 법칙 검증?
This experiment is rated as Intermediate (High School). It takes approximately 60 minutes to complete.
What safety precautions are needed for 람베르트-베어 법칙 검증?
Key safety precautions include: CuSO₄ is an irritant — avoid skin contact; Do not pipette by mouth; Wipe cuvettes with lint-free tissue before measurements.
What materials are needed for 람베르트-베어 법칙 검증?
The main materials required are: Copper sulfate (CuSO₄·5H₂O), Distilled water, Unknown CuSO₄ solution.
What results should I expect from 람베르트-베어 법칙 검증?
The plot should show a linear relationship (straight line through the origin) for the standard solutions. The unknown concentration is read from the x-axis at the corresponding absorbance on the calibration curve.