To determine the oxidation state of chlorine in HClO3 chloric acid , we can use the oxidation state rules and the fact that the sum of the oxidation states of all atoms in a neutral molecule must be equal to zero.1. The oxidation state of hydrogen H in a compound is usually +1.2. The oxidation state of oxygen O in a compound is usually -2.Now, let's assign oxidation states to the atoms in HClO3:H: +1O: -2 and there are 3 oxygen atoms, so the total for oxygen is -6 Cl: x unknown oxidation state of chlorine Now, we can set up an equation using the fact that the sum of the oxidation states must be equal to zero: +1 + -6 + x = 0Solving for x:x = 5So, the oxidation state of chlorine in HClO3 is +5.