O standing for oxygen can have multiple oxidation numbers depending on what it is bonded to, in most cases it has a negative 2 oxidation number but in certain cases like peroxides it can have a negative 1 oxidation state.
Oxidation numbers in Fe2O3 are respectively: Fe => +3 and O => -2
In NaBrO2, the oxidation numbers are as follows: Na is +1, Br is +5, O is -2.
In KMnO4, the oxidation numbers are: K(+1), Mn(+7), and O(-2).
In ClO4-, the oxidation number of Cl is +7, and the oxidation number of each O is -2.
The oxidation numbers in PO43- , phosphorus oxidation number=+5; oxygen = -2
In KO2, O has an oxidation number of -1, K has an oxidation number of +1. In CO2, O has an oxidation number of -2, C has an oxidation number of +4. In K2CO3, O has an oxidation number of -2, C has an oxidation number of +4, and K has an oxidation number of +1. In the given reaction, the oxidation numbers for each atom remain the same as in their individual compounds.
The oxidation numbers for the atoms in magnesium oxide are: Mg+2 and O-2.
In aluminum oxide (Al₂O₃), the oxidation number of aluminum (Al) is +3, while the oxidation number of oxygen (O) is -2. Since there are two aluminum atoms contributing a total of +6 and three oxygen atoms contributing a total of -6, the compound is electrically neutral, confirming these oxidation states. Thus, the oxidation numbers are +3 for Al and -2 for O.
The oxidation numbers of each element in HNO3 are: H is +1, N is +5, and O is -2. The sum of the oxidation numbers in a neutral compound like HNO3 must equal zero.
+2 for Mg +4 for C -2 for each O
In SOCl2, the oxidation numbers are as follows: Sulfur (S) has an oxidation number of +4 Oxygen (O) has an oxidation number of -2 Chlorine (Cl) has an oxidation number of -1
The oxidation number of sulfur in Li2SO4 is +6. This is because the oxidation numbers of Li and O are +1 and -2 respectively, and in a neutral compound the sum of all oxidation numbers must equal zero.