Question

A student took a solution of Copper sulfate in a beaker and put a clean Iron nail into it and left it for about an hour.

(a) What changes do you expect?

(b) Are these changes chemical in nature?

(c) Write a word equation for the chemical change, if any.

Answer 1

(A): Displacement reaction

1. Displacement reaction is the reaction in which a more reactive element displaces a less reactive element.
2. When an iron nail dipped in copper sulfate solution develops a brown copper coating of iron sulfate, this iron nail loses its shiny appearance.
3. Also, the copper sulfate solution's color changes from light blue to light green.
4. This means that iron is more reactive than copper because iron enters the solution while copper is displaced from its solution.$\underset{\mathrm{Iron}}{\mathrm{Fe}\left(\mathrm{s}\right)}+\underset{\mathrm{Copper}\mathrm{sulfate}}{{\mathrm{CuSO}}_4\left(\mathrm{l}\right)}\to \underset{\mathrm{Iron}\mathrm{sulfate}}{{\mathrm{FeSO}}_4\left(\mathrm{s}\right)}+\underset{\mathrm{Copper}}{\mathrm{Cu}}$

(B): Chemical changes:

1. A chemical change is the change of one substance into another, creating new compounds or new materials with different properties.
2. This is a chemical change as a new compound i.e. Iron sulfate is formed with completely new properties from iron.
3. Also, it is an irreversible reaction.

(C): Reaction:

$\underset{\left(\mathrm{Blue}\right)}{\mathrm{Copper}\mathrm{sulfate}\left(\mathrm{aq}\right)}+\mathrm{Iron}\left(\mathrm{s}\right)\to \underset{\left(\mathrm{Green}\right)}{\mathrm{Iron}\mathrm{sulfate}\left(\mathrm{aq}\right)}+\mathrm{Copper}\left(\mathrm{s}\right)$