Video Transcript
Galvanization is the process by
which iron or steel is coated in a thin layer of a second metal in order to prevent
corrosion. Which period four d-block metal is
used to provide this coating? (A) Scandium, (B) titanium, (C)
nickel, (D) zinc, or (E) chromium.
In this question, we want to know
which period four metal from the d-block is used in the process of
galvanization.
Galvanization is the process of
applying a protective coating of zinc over another metal, most often iron or
steel. Zinc specifically is utilized
because it is both abundant and is highly resistant to corrosion but will be
oxidized in preference to iron. In other words, zinc is more
reactive than iron.
The reactivity series shows some
metals, and the arrow shows that metals higher on the list are more reactive or are
more easily oxidized than metals lower on the list. Notice zinc is higher than iron on
this reactivity series. So, because of zinc’s higher
reactivity, along with its abundance, this makes it an effective and suitable metal
to protect iron with.
Since the zinc is oxidized to zinc
two plus ions more readily than iron is oxidized, the zinc provides electrons to the
iron, thus keeping the iron from rusting. We say the zinc is a sacrificial
metal since its integrity is sacrificed to protect the iron and prevent the iron
from corroding.
Galvanization is used in many
different products, such as buckets, watering cans, fence posts, bridges, and many
more. So, which period four d-block metal
is used in galvanization? The answer is (D), zinc.
