Question

The formula for quick lime is ___ $\left[\mathrm{CaO},\mathrm{Ca}{\left(\mathrm{OH}\right)}_2\right]$.

Answer 1

Writing Chemical Formula:

The following rules are followed to write a chemical formula:

1. First, the valencies of both the elements present are noted.
2. The valances are cross multiplied and the formula is written in the lowest common multiple of the two valencies.

Calcium oxide is referred to as quicklime. It consists of Ca (Calcium) and ${\mathrm{O}}_2$ (Oxygen). Both calcium and oxygen have a valency of 2. So, its count of atoms is in a 1:1 ratio. Thus, the formula is CaO.

So, the formula for quick lime is CaO.