浓差电池

利用浓度差产生电压

Electrochemistry Advanced (University) 45 分钟 ~$18.00

目标

用不同浓度的铜半电池构建浓差电池，验证能斯特方程对电池电位的预测。

背景

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.

安全警告

  • Copper sulfate is toxic
  • Wear gloves when handling solutions

所需PPE

goggles gloves lab_coat

材料

  • 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

设备

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

步骤

1

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

5 分钟 Wear gloves
2

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

3 分钟
3

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

2 分钟
4

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

3 分钟
5

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

5 分钟
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 分钟
7

Compare measured and theoretical values. Discuss sources of deviation.

5 分钟

预期结果

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.

清理

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

详情

类别
Electrochemistry
难度
Advanced (University)
时长
45 分钟
预估费用
$18.00
步骤数
7
材料
3

更多实验

丹尼尔电池的构建 45 min 伏打电池电动势测量 60 min 柠檬电池 20 min 水的电解 40 min 活动性序列验证 30 min 硫酸铜电解 50 min 铜电镀 60 min 防锈方法比较 30 min

Frequently Asked Questions

What is the objective of 浓差电池?
用不同浓度的铜半电池构建浓差电池，验证能斯特方程对电池电位的预测。
How difficult is 浓差电池?
This experiment is rated as Advanced (University). It takes approximately 45 minutes to complete.
What safety precautions are needed for 浓差电池?
Key safety precautions include: Copper sulfate is toxic; Wear gloves when handling solutions.
What materials are needed for 浓差电池?
The main materials required are: Copper(II) sulfate (CuSO₄), Copper strips (2), Potassium nitrate salt bridge.
What results should I expect from 浓差电池?
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.