बीयर-लैम्बर्ट नियम का सत्यापन

अवशोषण और सांद्रता के बीच रैखिक संबंध प्रदर्शित करना

Colorimetry Intermediate (High School) 60 मिनट ~$12.00

उद्देश्य

विभिन्न सांद्रता पर CuSO₄ विलयनों का अवशोषण मापकर और अंशांकन वक्र बनाकर बीयर-लैम्बर्ट नियम को सत्यापित करें।

पृष्ठभूमि

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.

सुरक्षा चेतावनियाँ

  • 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

आवश्यक PPE

goggles lab_coat

सामग्री

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

उपकरण

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

प्रक्रिया

1

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

5 मिनट
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 मिनट
3

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

3 मिनट
4

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

2 मिनट
5

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

15 मिनट
6

Measure the absorbance of the unknown solution.

5 मिनट
7

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

20 मिनट

अपेक्षित परिणाम

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.

सफाई

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

विवरण

श्रेणी
Colorimetry
कठिनाई
Intermediate (High School)
अवधि
60 मिनट
अनुमानित लागत
$12.00
चरण
7
सामग्री
3

अधिक प्रयोग

एस्पिरिन का स्पेक्ट्रोफोटोमेट्रिक निर्धारण 75 min कलरिमेट्रिक प्रोटीन परख (ब्रैडफोर्ड विधि) 60 min ग्लूकोज का कलरिमेट्रिक निर्धारण 60 min पानी में लोहे का निर्धारण 75 min फॉस्फेट का कलरिमेट्रिक निर्धारण 90 min मिश्रण का स्पेक्ट्रोफोटोमेट्रिक विश्लेषण 75 min स्पेक्ट्रोफोटोमेट्री द्वारा खाद्य रंग विश्लेषण 60 min

Frequently Asked Questions

What is the objective of बीयर-लैम्बर्ट नियम का सत्यापन?
विभिन्न सांद्रता पर CuSO₄ विलयनों का अवशोषण मापकर और अंशांकन वक्र बनाकर बीयर-लैम्बर्ट नियम को सत्यापित करें।
How difficult is बीयर-लैम्बर्ट नियम का सत्यापन?
This experiment is rated as Intermediate (High School). It takes approximately 60 minutes to complete.
What safety precautions are needed for बीयर-लैम्बर्ट नियम का सत्यापन?
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 बीयर-लैम्बर्ट नियम का सत्यापन?
The main materials required are: Copper sulfate (CuSO₄·5H₂O), Distilled water, Unknown CuSO₄ solution.
What results should I expect from बीयर-लैम्बर्ट नियम का सत्यापन?
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.