WAEC - Chemistry (2004 - No. 34)

What is the change in the oxidation number of 1^- in the reaction represented by the following equation? 51 ^-1_(aq) + 6H⁺_(aq) + 1O^-_3(aq) → 31_2(g) + 3H₂O_(l)

-5 to -3

-1 to 0