Chapter U1.22, Problem 2E

Interpretation Introduction

Interpretation:

The presence of the polyatomic ion in a compound by its chemical formula should be predicted.

Concept introduction:

Ion that is covalently bonded with the two or more atoms and considered as a single unit and also has net charge on it, is known as polyatomic ions.

Answer to Problem 2E

The polyatomic ion can be predicted by their constituent ions when the compound is to be dissociated into ions.

Explanation of Solution

The ion that is made up of more than one atom is known as polyatomic ions. It can be seen from the name polyatomic where poly-means many and atomic means-atoms. Also, ions mean they have charge on them.

If the compound contain polyatomic ion, it can be predicted by their constituent ions when the compound is to be dissociated into ions.

For example, ${\text{CaCO}}_{\text{3}}$ and ${\text{CaCl}}_2$. Both the compounds contain Ca as a metal, it has + 2 charge. If the compounds are dissociated the ions would be ${\text{Ca}}^{2+}$, ${\text{CO}}_{\text{3}}{}^{2-}$ for ${\text{CaCO}}_{\text{3}}$ and ${\text{Ca}}^{2+}$, ${\text{Cl}}^{-}$ for ${\text{CaCl}}_2$. Chloride ion is not polyatomic ion but ${\text{CO}}_{\text{3}}{}^{2-}$ is a polyatomic ion. Hence, the compound ${\text{CaCO}}_{\text{3}}$ contains polyatomic ion.

Conclusion

The polyatomic ion can be predicted by their constituent ions when the compound is to be dissociated into ions.