Answer:
+2
Explanation:
Oxidation number of an element, also called its oxidation state, is the number of electrons its atoms lost or gain in the process of forming a chemical compound.
To determine the oxidation state of an element or compound;
- The sum of all the oxidation numbers in a neutral compound must equal zero (0).
In the compound: Fe2(CO3)2
This compound is a neutral one, hence, its oxidation state is equal to zero (0).
It contains a polyatomic ion (carbonate ion) i.e. CO3 2-, whose net charge is -2.
Hence, to find the oxidation number of Iron (Fe), which is represented by X, in the compound, we say;
X(2) + -2(2) = 0
2X + -4 = 0
2X - 4 = 0
2X = 4
X = +2
Therefore, the oxidation number of Fe in Fe2(CO3)2 is (+2)
The compound Fe2(CO3)2 is called Iron (II) carbonate
