Question

Complete and balance the following equation:

$\mathrm{Fe}+{\mathrm{O}}_2\stackrel{\mathrm{Moisture}}{\to }\mathrm{\_\_\_\_\_\_}$

Answer 1

Reaction of moist air with Iron:

• When iron is exposed to moist air it reacts with the oxygen present in the air to form ferrous oxide.
• This is a brown flaky layer coating formed on iron and causes the destruction of iron.
• This formation is known as rust, and the process is known as rusting.

$\underset{\mathrm{Iron}}{\mathrm{Fe}\left(\mathrm{s}\right)}+\underset{\mathrm{Oxygen}}{{\mathrm{O}}_2\left(\mathrm{g}\right)}\stackrel{\mathrm{moisture}}{\to }\underset{\mathrm{Ferrous}\mathrm{oxide}}{{\mathrm{Fe}}_2{\mathrm{O}}_3\left(\mathrm{s}\right)}$

Balancing of chemical reaction:

• The number of atoms of different elements is present before balancing of reaction.

Atoms	Reactant	Product
Iron(Fe)	1	2
Oxygen(O)	2	3

• Multiply the Iron atom by 4 and the oxygen molecule by 3 and ferrous oxide by 2 to balance the reaction.

$\underset{\mathrm{Iron}}{4\mathrm{Fe}\left(\mathrm{s}\right)}+\underset{\mathrm{Oxygen}}{3{\mathrm{O}}_2\left(\mathrm{g}\right)}\stackrel{\mathrm{Moisture}}{\to }\underset{\mathrm{Ferrous}\mathrm{oxide}}{2{\mathrm{Fe}}_2{\mathrm{O}}_3\left(\mathrm{s}\right)}$

Atoms	Reactant	Product
Iron(Fe)	4	4
Oxygen(O)	6	6

• Hence, the balanced equation is:

$\underset{\mathrm{Iron}}{4\mathrm{Fe}\left(\mathrm{s}\right)}+\underset{\mathrm{Oxygen}}{3{\mathrm{O}}_2\left(\mathrm{g}\right)}\stackrel{\mathrm{Moisture}}{\to }\underset{\mathrm{Ferrous}\mathrm{oxide}}{2{\mathrm{Fe}}_2{\mathrm{O}}_3\left(\mathrm{s}\right)}$