Consider the unbalanced aqueous reaction

CHEMISTRY · Single correct · A Level · Chemistry · Oxidation, reduction and redox reactions · Oxidation, reduction and redox reactions

Problem

\mathrm{I_2 + S_2O_3^{2-} \rightarrow I^- + S_4O_6^{2-}}

. What is the coefficient in front of

\mathrm{S_2O_3^{2-}}

when the equation is balanced with the smallest whole-number coefficients? (a) 3 (b) 2 (c) 1 (d) 4