Answer is: reducin agent in this reaction is thiosulfate (S₂O₃²⁻).
Balanced chemical reaction: 2S₂O₃²⁻(aq) + I₂(aq) → S₄O₆²⁻(aq) + 2I⁻<span>(aq).
Reducing agent is element or compound who loose electrons in chemical reaction. Sulfur in </span>thiosulfate change oxidation number from +2 to +5 tetrathionate anion (two<span> sulfur </span>atoms in the ion have oxidation state<span> 0 and two atoms have oxidation state +5).</span>
I think one is Hydrochloric acid
A = Z + n
A = 12 + 10
A = 22
Answer C
hope this helps!
