13. Construction of electrochemical cells and measurement of Ecell

  • 00:36 What is a half-cell?
  • 00:52 What equilibrium exists in the two half-cells?
  • 00:57 Why is it important to have a high-resistance voltmeter?
  • 01:04 Why is the salt-bridge important?
  • 01:10 Which metal is the best at 'winning' electrons?
  • wires

  • crocodile clips

  • voltmeter

  • 2 x 100 cm³ beakers

  • filter-paper cut into a long strip

  • cu foil strip

  • zn foil strip

Hazard Risk Control measure

1mol dm-3 CuSOsolution

Contact with eyes 


Eye: flood with water (10 min)


1mol dm-3 ZnSO4 solution

Danger: corrosive (eyes)

Contact with eyes & skin

Eye: flood with water (10 min)
See doctor. 

Saturated KNO3 solution

Contact with eyes & skin. Ingestion. 

Warning: harmful (ingestion), irritant (skin, eyes, respiratory)

Eye: flood with water (10min)

See doctor if pain persists.

Skin: wash with plenty of water. 

Ingestion: see doctor