Question

gold and chlorine form the ionic 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:

In the common (trivial) naming system for ionic compounds with gold, gold can have two oxidation states: +1 (aurous) and +3 (auric). For \( \text{AuCl}_3 \), gold has an oxidation state of +3 (since each Cl is -1, and 3 Cl⁻ ions give a total negative charge of -3, so Au must be +3 to balance). The common name for gold(III) chloride is auric chloride. Option B is gold(I) (oxidation state +1), which would correspond to \( \text{AuCl} \), not \( \text{AuCl}_3 \). Option C is aurous (gold(I)), and option D is the systematic name (using Roman numerals), but the question asks for the common system. So the correct common name is auric chloride.

Answer:

A) Auric chloride