Required practical 8: measuring the EMF of an electrochemical cell

Describe the experiment to measure the EMF of an electrochemical cell

• clean electrodes to remove protective oxide layer

• Place copper strip in 50cm3of 1molddm-3 copper sulfate

• Place zinc strip in 50cm3 of zinc sulfate

• Use a strip of filter paper soaked in potassium nitrate for the salt bridge

• Connect half cells by connecting the metals with crocodile clips

What is the purpose of the salt bride

-allows free moving ions to conduct a charge

Why wouldn’t you use potassium chloride as the salt bridge?

• chloride ions can form complexes with the copper ions

Why wouldn’t you use a wire?

• the metal wire would set up its own electrode

Why would you use a platinum electrode?

• unreactive/inert and can conduct electricity