Question

Why is calcium dichloride not the correct systematic name for \(\mathrm{CaCl}_{2} ?\)

Short answer

The correct systematic name for \(\mathrm{CaCl}_{2}\) is calcium chloride, not calcium dichloride. The use of prefixes like "di" or "tri" is not necessary when naming ionic compounds, as the name should simply reflect the metal and non-metal ions involved.

Step-by-step solution

Identify the compound

The given compound is \(\mathrm{CaCl}_{2}\). It is an ionic compound formed between calcium (Ca), a metal, and chlorine (Cl), a non-metal.

Review the nomenclature rules for ionic compounds

When naming ionic compounds, the name must reflect the ratio of the metal and non-metal ions. The name of the metal ion comes first. In this case, it's calcium. The non-metal ion name follows the metal ion and changes its ending to -ide. In this case, it's chlorine, which changes to chloride.

Apply the rules of nomenclature

Following the naming rules, we can see that our metal ion is calcium, and our non-metal ion is chloride. Since there's no need to mention the subscript "2" in the name, the correct systematic name for this compound is calcium chloride, not calcium dichloride.

Conclusion

The correct systematic name for \(\mathrm{CaCl}_{2}\) is calcium chloride, not calcium dichloride. We don't use prefixes like "di" or "tri" when naming ionic compounds.