Измерение потенциала гальванической ячейки

Измерение ЭДС различных комбинаций полуэлементов

Electrochemistry Advanced (University) 60 мин ~$25,00

Цель

Измерить электродвижущую силу (ЭДС) нескольких комбинаций гальванических ячеек и сравнить со стандартными значениями потенциалов восстановления.

Предпосылки

By constructing galvanic cells with different metal/metal-ion half-cell combinations and measuring their voltages, students can experimentally determine relative electrode potentials. Comparing measured values with standard reduction potentials validates electrochemical theory.

Предупреждения по безопасности

  • Lead compounds are toxic — handle with extreme care
  • Wear nitrile gloves throughout
  • Wash hands immediately if lead solution contacts skin
  • Dispose of lead waste in designated containers

Требуемые СИЗ

goggles gloves lab_coat

Материалы

  • Zinc strip and 1M ZnSO₄ (100 mL)
  • Copper strip and 1M CuSO₄ (100 mL)
  • Lead strip and 1M Pb(NO₃)₂ (100 mL)
    Toxic
  • Tin strip and 1M SnCl₂ (100 mL)
  • KNO₃ salt bridge solution (200 mL)
    Saturated
  • Filter paper strips (10)
    For salt bridges

Оборудование

Six 250 mL beakers High-impedance voltmeter or multimeter Wires with alligator clips Sandpaper

Процедура

1

Sand all metal strips until shiny. Prepare 1M solutions of each metal salt in separate beakers.

5 мин Wear gloves for lead compounds
2

Prepare salt bridges by soaking filter paper strips in saturated KNO₃ solution.

3 мин
3

Construct a Zn/Cu cell: connect with a salt bridge and measure the EMF with the voltmeter.

5 мин
4

Construct a Zn/Pb cell and measure EMF.

5 мин Handle lead carefully
5

Construct a Zn/Sn cell and measure EMF.

5 мин
6

Construct a Cu/Pb cell and measure EMF.

5 мин
7

Construct a Sn/Cu cell and measure EMF.

5 мин
8

Tabulate all results. Calculate theoretical EMF values using standard reduction potentials and compare with measured values.

15 мин

Ожидаемые результаты

Zn/Cu: ~1.10 V, Zn/Pb: ~0.63 V, Zn/Sn: ~0.62 V, Cu/Pb: ~0.47 V, Sn/Cu: ~0.48 V. Measured values should be within 0.05-0.15 V of theoretical due to non-standard conditions.

Уборка

Collect all lead-containing waste in designated containers. Dispose of copper waste separately. Rinse metal strips and store. Wash hands thoroughly.

Детали

Категория
Electrochemistry
Сложность
Advanced (University)
Продолжительность
60 мин
Прим. стоимость
$25,00
Шаги
8
Материалы
6

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Frequently Asked Questions

What is the objective of Измерение потенциала гальванической ячейки?
Измерить электродвижущую силу (ЭДС) нескольких комбинаций гальванических ячеек и сравнить со стандартными значениями потенциалов восстановления.
How difficult is Измерение потенциала гальванической ячейки?
This experiment is rated as Advanced (University). It takes approximately 60 minutes to complete.
What safety precautions are needed for Измерение потенциала гальванической ячейки?
Key safety precautions include: Lead compounds are toxic — handle with extreme care; Wear nitrile gloves throughout; Wash hands immediately if lead solution contacts skin.
What materials are needed for Измерение потенциала гальванической ячейки?
The main materials required are: Zinc strip and 1M ZnSO₄, Copper strip and 1M CuSO₄, Lead strip and 1M Pb(NO₃)₂, Tin strip and 1M SnCl₂, KNO₃ salt bridge solution.
What results should I expect from Измерение потенциала гальванической ячейки?
Zn/Cu: ~1.10 V, Zn/Pb: ~0.63 V, Zn/Sn: ~0.62 V, Cu/Pb: ~0.47 V, Sn/Cu: ~0.48 V. Measured values should be within 0.05-0.15 V of theoretical due to non-standard conditions.