Question

mastery quiz: ionic bonding

1. which is the appropriate name for cacl₂?

(a) calcium (ii) chloride
(c) calcium chlorate
(b) calcium (iv) chloride
(d) calcium chloride

Explanation:

To determine the correct name for \( \text{CaCl}_2 \), we use the rules for naming ionic compounds. Calcium (Ca) has a +2 charge (group 2 metal, so it forms \( \text{Ca}^{2+} \)). Chloride (\( \text{Cl}^- \)) has a -1 charge. In the compound, we need two \( \text{Cl}^- \) to balance one \( \text{Ca}^{2+} \) (since \( 2\times(-1)+(+2) = 0 \)). For ionic compounds with a metal (calcium, a main - group metal with a fixed charge) and a non - metal (chlorine), we use the name of the metal followed by the name of the non - metal with the suffix “-ide”. So calcium (Ca) combines with chloride (\( \text{Cl}^- \)) to form calcium chloride. Let's analyze the options:

• Option A: “Calcium (II) chloride” is incorrect because calcium, being a group 2 metal, has a fixed +2 charge, and we don't use Roman numerals for metals with fixed charges.
• Option B: “Calcium (IV) chloride” is incorrect as calcium does not have a +4 charge.
• Option C: “Calcium chlorate” is incorrect because chlorate is \( \text{ClO}_3^- \), and this compound contains \( \text{Cl}^- \), not \( \text{ClO}_3^- \).
• Option D: “Calcium chloride” is correct as it follows the naming rules for ionic compounds with a metal of fixed charge and a non - metal (using the “-ide” suffix for the non - metal ion).

Answer:

D. Calcium chloride