Please enable JavaScript.
Coggle requires JavaScript to display documents.
Uses of the reactivity series (Metals- Part 3) - Coggle Diagram
Uses of the reactivity series
(Metals- Part 3)
Thermite process:
It is used to repair broken trail and tram lines. Molten iron runs into the cracks and gaps in the rail and hardens.
This requires
Iron (III) oxide and aluminium.
Making simple cells:
A charge generating cell
E.g.
Solution of NaCl, Magnesium electrode (-ve terminal), Copper electrode (+ve terminal) and a bulb.
The more reactive metal becomes the (-ve) terminal.
Electrons move
from magnesium electrode to copper electrode.
Since
magnesium
prefers to stay in its ionic form, it undergoes
reduction
.
These
2e- move to the copper electrode
.
Hydrogen from the solution undergoes reduction.
Hydrogen gas is formed near the copper electrode.
Since there is movement of electrons, the electricity is generated.
The more the difference between the positions of the metals in the reactivity series, the higher the voltage.
Sacrificial protection of iron:
Used in oil rigs
Large blocks of Zn are present on the Fe
Zinc keeps away water and air from iron.
Zinc is oxidised instead of iron.
It is called
sacrificial protection.
The zinc block must be replaced before it all dissolves away.
Galvanising:
Zinc is coated to iron/ steel.
Iron is dipped in a bath of molten zinc.
Zinc keeps water and air away
and prevents the iron from rusting.