Beer-Lambert Yasasının Doğrulanması

Absorbans ile konsantrasyon arasındaki doğrusal ilişkiyi gösterme

Colorimetry Intermediate (High School) 60 dak ~$12,00

Hedef

Farklı konsantrasyonlardaki CuSO₄ çözeltilerinin absorbansını ölçerek ve bir kalibrasyon eğrisi oluşturarak Beer-Lambert yasasını doğrulamak.

Arka Plan

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.

Güvenlik Uyarıları

  • 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

Gerekli KKD

goggles lab_coat

Malzemeler

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

Ekipman

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

Prosedür

1

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

5 dak
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 dak
3

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

3 dak
4

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

2 dak
5

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

15 dak
6

Measure the absorbance of the unknown solution.

5 dak
7

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

20 dak

Beklenen Sonuçlar

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.

Temizlik

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

Ayrıntılar

Kategori
Colorimetry
Zorluk
Intermediate (High School)
Süre
60 dak
Tahmini Maliyet
$12,00
Adımlar
7
Malzemeler
3

Daha Fazla Deney

Aspirinin Spektrofotometrik Tayini 75 min Fosfat Kolorimetrik Tayini 90 min Glukozun Kolorimetrik Tayini 60 min Karışımın Spektrofotometrik Analizi 75 min Kolorimetrik Protein Analizi (Bradford Yöntemi) 60 min Spektrofotometreyle Gıda Boyası Analizi 60 min Sudaki Demir Tayini 75 min

Frequently Asked Questions

What is the objective of Beer-Lambert Yasasının Doğrulanması?
Farklı konsantrasyonlardaki CuSO₄ çözeltilerinin absorbansını ölçerek ve bir kalibrasyon eğrisi oluşturarak Beer-Lambert yasasını doğrulamak.
How difficult is Beer-Lambert Yasasının Doğrulanması?
This experiment is rated as Intermediate (High School). It takes approximately 60 minutes to complete.
What safety precautions are needed for Beer-Lambert Yasasının Doğrulanması?
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 Beer-Lambert Yasasının Doğrulanması?
The main materials required are: Copper sulfate (CuSO₄·5H₂O), Distilled water, Unknown CuSO₄ solution.
What results should I expect from Beer-Lambert Yasasının Doğrulanması?
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.