Electrochemical cells Flashcards
why are the metal/graphite strips cleaned with sandpaper in a half cell?
to expose the surface area for reactions to occur.
why is a salt bridge needed?
to complete the circuit.
how is grease and oil removed from the metal strips?
using propanone
how is a salt bridge made?
soak a strip of filter paper in KNO3.
what are the standard conditions for a half cell?
- 1 moldm-3
- 100 kPa / 1atm
- 298K
if a reaction is feasible emf is …..?
+ve
if a reaction isn’t feasible emf is …..?
-ve
Ecell =
reduction - oxidation
give an example of a solution too dangerous to use at 1 moldm-3
AgNO3
zinc sulphate and iron (II) sulphate are…?
harmful to the environment
why must electrodes be made of inert substances?
so they do not interfere and react.
cannot react with water. e.g. like Mg does.
why might experimental and theoretical values be different?
conditions are not standard.
