familiarize oneself with some more common instances of corrosion.
acid 0.1 M; sulphuric acid 0.1 M; zinc
granules; copper wire
of copper(II) sulphate; solution of copper(II)
chloride; solution of iron
(II) sulphate; solution of potassium
hexacyanoferrate(III); zinc-plated iron sheet; tin-plated iron sheet;
tubes, small beaker (50 cm3),
Making of a galvanic pair
a zinc granule on the bottom
of the centrifuge tube and pour
solution of hydrochloric acid on top. Write down the equation of
reaction which occurs. Which compound is the oxidant, which is the
reductant?Oxidant is H: Reductant is Zn:
the copper wire into the same
solution in the centrifuge tube,
ensuring that it will not touch
the zinc granule. Observe whether any hydrogen
evolves on the copper surface? Explain
, why copper did not react
with diluted hydrochloric acid!
Adding copper wire doesnt make H extract. Copper is less active than H. H
starts to extract when connect copper wire to Zinc, because zinc
corrodes when connected to more active metal .