In the compound Na2SO4, the oxidation state of sodium Na is +1 and the oxidation state of oxygen O is -2. The compound has a neutral charge, so the sum of the oxidation states of all the elements in the compound must equal zero.Let's denote the oxidation state of sulfur S as x. The compound has 2 sodium atoms, 1 sulfur atom, and 4 oxygen atoms. Using the oxidation states, we can set up an equation:2 +1 + x + 4 -2 = 0Solving for x:2 + x - 8 = 0x - 6 = 0x = +6The oxidation state of sulfur in Na2SO4 is +6.