Question

Write the molecular formula of

Cuprous oxide.

Answer 1

Molecular formula: molecular formula of a compound is the symbolic representation of the one molecule of a compound which shows the number of atom of each element that is present in it.

For example, ${\mathrm{H}}_2\mathrm{O}$(water) molecule represents that water is made up of 2 atoms of hydrogen element and one atom of oxygen.

Cuprous oxide:

• First, write symbols of copper (positive ion towards the right) and oxygen (negative ion towards left).

$\mathrm{Cu}$ (copper) $\mathrm{O}$(oxygen)

• Write the valency of ions below them.

$\mathrm{Cu}$ (copper) $\mathrm{O}$(oxygen)

(+1) (-2)

• Now interchange the valency by the criss-cross method and write interchange valency at the base of each ion.
• Thus the formula becomes${\mathrm{Cu}}_2\mathrm{O}$.