Construcción de la Celda de Daniell

Construcción de la clásica celda galvánica zinc-cobre

Electrochemistry Intermediate (High School) 45 min ~$20,00

Objetivo

Construir una celda de Daniell para medir el potencial estándar de celda y observar las reacciones electroquímicas en cada electrodo.

Antecedentes

The Daniell cell is a classic electrochemical cell that uses zinc and copper half-cells connected by a salt bridge. Zinc is oxidized at the anode while copper ions are reduced at the cathode. The theoretical cell potential is 1.10 V under standard conditions.

Advertencias de seguridad

  • Copper sulfate is toxic if ingested
  • Wear gloves when handling copper sulfate solution
  • Handle hot agar solution with care

EPP requerido

goggles gloves lab_coat

Materiales

  • Zinc sulfate (ZnSO₄) (100 mL)
    1M solution
  • Copper(II) sulfate (CuSO₄) (100 mL)
    1M solution
  • Zinc strip (1 piece)
    Sanded clean
  • Copper strip (1 piece)
    Sanded clean
  • Potassium nitrate (KNO₃) (10 g)
    For salt bridge
  • Agar powder (2 g)
    For salt bridge
  • Insulated wire with clips (50 cm)

Equipamiento

Two 250 mL beakers U-tube or cotton wick Multimeter Sandpaper Hot plate

Procedimiento

1

Prepare the salt bridge: dissolve 5 g KNO₃ and 2 g agar in 30 mL hot water. Pour into a U-tube and allow to set.

10 min Handle hot liquids carefully
2

Sand the zinc and copper strips until shiny to ensure good contact.

3 min
3

Pour 100 mL of 1M ZnSO₄ into one beaker and 100 mL of 1M CuSO₄ into the other.

2 min Wear gloves for CuSO₄
4

Place the zinc strip in the ZnSO₄ solution and the copper strip in the CuSO₄ solution.

2 min
5

Connect the two beakers with the salt bridge.

2 min
6

Connect the multimeter between the zinc (negative) and copper (positive) terminals. Measure the cell voltage.

3 min
7

Observe both electrodes over 15 minutes. Note any color changes in the solutions and deposits on the electrodes.

15 min
8

Record the voltage and observations. Compare the measured EMF with the theoretical value of 1.10 V.

5 min

Resultados esperados

The cell should produce approximately 1.0-1.1 V. The zinc strip will slowly dissolve (oxidation), the blue CuSO₄ solution will become lighter, and copper metal will deposit on the copper strip (reduction).

Limpieza

Dispose of copper sulfate solution in heavy metal waste. Rinse and dry the metal strips for reuse. Clean the salt bridge.

Frequently Asked Questions

What is the objective of Construcción de la Celda de Daniell?
Construir una celda de Daniell para medir el potencial estándar de celda y observar las reacciones electroquímicas en cada electrodo.
How difficult is Construcción de la Celda de Daniell?
This experiment is rated as Intermediate (High School). It takes approximately 45 minutes to complete.
What safety precautions are needed for Construcción de la Celda de Daniell?
Key safety precautions include: Copper sulfate is toxic if ingested; Wear gloves when handling copper sulfate solution; Handle hot agar solution with care.
What materials are needed for Construcción de la Celda de Daniell?
The main materials required are: Zinc sulfate (ZnSO₄), Copper(II) sulfate (CuSO₄), Zinc strip, Copper strip, Potassium nitrate (KNO₃).
What results should I expect from Construcción de la Celda de Daniell?
The cell should produce approximately 1.0-1.1 V. The zinc strip will slowly dissolve (oxidation), the blue CuSO₄ solution will become lighter, and copper metal will deposit on the copper strip (reduction).