In NaClO3, the oxidation state of sodium Na is +1, and the oxidation state of oxygen O is -2. Let's denote the oxidation state of chlorine Cl as x. The overall charge of the compound NaClO3 is neutral 0 . Therefore, the sum of the oxidation states of all the elements in the compound must equal zero. So, we have: +1 + x + 3 -2 = 0Solving for x:x - 6 = -1x = +5The oxidation state of chlorine in NaClO3 is +5.