Question

gold and chlorine form the lonic compound aucl₃. whats the name of this compound in the common system?
a) auric chloride
b) gold(i) chloride
c) aurous chloride
d) gold(iii) chloride

Explanation:

1. First, recall the common naming system for ionic compounds with metals having variable oxidation states. For gold, the common (trivial) names use "auric" for the +3 oxidation state and "aurous" for the +1 oxidation state.
2. In \( \text{AuCl}_3 \), let the oxidation state of Au be \( x \). Chlorine has an oxidation state of -1. So, \( x + 3(-1)=0 \), which gives \( x = +3 \).
3. Now, analyze the options:

• Option B: Gold(I) chloride implies Au has +1 oxidation state, which is incorrect for \( \text{AuCl}_3 \).
• Option C: Aurous chloride is for Au in +1 oxidation state, so incorrect.
• Option D: Gold(III) chloride is the systematic name (using Roman numerals), but the question asks for the common system.
• Option A: Auric chloride is the common name for gold in the +3 oxidation state (since \( \text{AuCl}_3 \) has Au in +3), so this is correct.

Answer:

A) Auric chloride