Question

Write the formulae of the following compounds:

Copper carbonate

Answer 1

To write the formulae of an Ionic compound we follow the given steps:

1. Write the symbols for the ions present in the compound.
2. Write their respective valencies below the symbols along with the charge.
3. Reduce the valency to a simple ratio by dividing it with a common factor.
4. Using the criss-cross method, assign the second valency to the first ion and the first valency to the second ion.
5. For complete formula, write the numerals in the subscript of the symbols of ions. Write the symbol of the second ion in a bracket.

The formula of Copper carbonate will be :

Name of ions: Copper carbonate

Symbols of ions: $\mathrm{Cu}$ ${\mathrm{CO}}_3$

Valency of elements: +2 -2

Formula: ${\mathrm{CuCO}}_3$ (+2 and -2 cancel each other)