خلية التركيز

توليد جهد من فروق التركيز

Electrochemistry Advanced (University) 45 دقيقة ~$18,00

الهدف

بناء خلية تركيز باستخدام نصفي خلية نحاس بتركيزات مختلفة والتحقق من تنبؤ معادلة نيرنست لإمكانية الخلية.

الخلفية

A concentration cell generates voltage from the difference in concentration between two otherwise identical half-cells. According to the Nernst equation, the EMF depends on the logarithm of the concentration ratio. This experiment demonstrates that even without different metals, a potential difference arises from entropy-driven mixing.

تحذيرات السلامة

  • Copper sulfate is toxic
  • Wear gloves when handling solutions

معدات الوقاية الشخصية المطلوبة

goggles gloves lab_coat

المواد

  • Copper(II) sulfate (CuSO₄) (200 mL total)
    Prepare 0.01M and 1M solutions
  • Copper strips (2) (2 pieces)
    Identical, sanded clean
  • Potassium nitrate salt bridge (1)
    Saturated KNO₃ in agar

المعدات

Two 250 mL beakers High-impedance voltmeter Wires with alligator clips Sandpaper Volumetric flasks

الإجراء

1

Prepare two CuSO₄ solutions: 100 mL of 1.0M and 100 mL of 0.01M.

5 دقيقة Wear gloves
2

Sand both copper strips until shiny and rinse with distilled water.

3 دقيقة
3

Pour the dilute (0.01M) CuSO₄ into one beaker and the concentrated (1.0M) into the other.

2 دقيقة
4

Place one copper strip in each beaker. Connect with the salt bridge.

3 دقيقة
5

Connect the voltmeter. The dilute side is the anode (negative terminal). Measure the EMF.

5 دقيقة
6

Calculate the predicted EMF using the Nernst equation: E = (RT/nF) ln(C_high/C_low) = (0.0257/2) ln(100) = 0.059 V at 25°C.

5 دقيقة
7

Compare measured and theoretical values. Discuss sources of deviation.

5 دقيقة

النتائج المتوقعة

The cell should produce approximately 0.05-0.06 V. The Nernst equation predicts E = (0.02569 V / 2) x ln(1.0/0.01) = 0.059 V at 25°C. Measured values may be slightly lower due to junction potentials.

التنظيف

Dispose of copper sulfate waste in designated containers. Rinse and store copper strips. Clean salt bridge.

Frequently Asked Questions

What is the objective of خلية التركيز?
بناء خلية تركيز باستخدام نصفي خلية نحاس بتركيزات مختلفة والتحقق من تنبؤ معادلة نيرنست لإمكانية الخلية.
How difficult is خلية التركيز?
This experiment is rated as Advanced (University). It takes approximately 45 minutes to complete.
What safety precautions are needed for خلية التركيز?
Key safety precautions include: Copper sulfate is toxic; Wear gloves when handling solutions.
What materials are needed for خلية التركيز?
The main materials required are: Copper(II) sulfate (CuSO₄), Copper strips (2), Potassium nitrate salt bridge.
What results should I expect from خلية التركيز?
The cell should produce approximately 0.05-0.06 V. The Nernst equation predicts E = (0.02569 V / 2) x ln(1.0/0.01) = 0.059 V at 25°C. Measured values may be slightly lower due to junction potentials.