Answer:
0,31%
Explanation:
For the reaction:
I₂ + 2 S₂O₃²⁻ → 2 I⁻ + S₄O₆²⁻
0,043 L × 0,117 M of sodium tiosulfate = 5,031x10⁻³ moles of S₂O₃²⁻
5,031x10⁻³ moles of S₂O₃²⁻ × = <em>2,5156x10⁻³ moles of I₂</em>
These moles of I₂ were produced from:
ClO⁻⁻ + 2 H⁺ + 2 I⁻ → I₂ + Cl⁻ + H2O
2,5156x10⁻³ moles of I₂ ≡ moles of NaClO
2,5156x10⁻³ moles of NaClO × =<em> 0,187 g of NaClO</em>
Thus, percentage composition by mass is:
=<em> 0,31%</em>
I hope it helps!