The oxidation state of sulphur in H2S2O8 is, x+2(−2)+1(−1)+1(−1)‌‌=0 x‌‌=+6 The oxidation state of sulphur in H2SO5 is, x+2(−2)+1(−1)+1(−1)=0 x=+6 The oxidation state of sulphur in H2SO3 is, x+2(−1)+1(−2)‌‌=0 x‌‌=+4 The oxidation state of sulphur in H2SO4 is, x+2(−1)+1(−2)=0 x=+4 The oxidation state of sulphur in H2S2O7 is, x+2(−2)+1(−1)+1(−1)=0 x=+6 The oxidation state of sulphur in SO2Cl2 is, x+2(−2)+1(−1)+1(−1)=0 x=+6 The oxidation state of sulphur in SOCl2 is, x+1(−2)+2(−1)=0 x=+4 Thus, the compound having +6O.S is 4