Step 1: Identify Reaction Type
Reaction: Arsenic(III) oxide with hydrogen sulfide yields arsenic sulfide (\( As_2S_3 \)).
Step 2: Balance Reaction
\[ As_2O_3 + 3H_2S \rightarrow As_2S_3 + 3H_2O \] Arsenic oxide is reduced to arsenic sulfide; hydrogen sulfide is oxidized.
Final Answer: The resulting sol is arsenic sulfide (\( As_2S_3 \)).