Definition of oxidation number

Oxidation number, also known as oxidation state, is a measure of the degree of oxidation of an atom in a chemical compound. It is defined as the charge that an atom would have if all the bonding electrons were shared equally between the atoms in the compound.

Calculation of oxidation number of iron in Na2[Fe(CN)5(NO )]

To calculate the oxidation number of iron in Na2[Fe(CN)5(NO )], we need to assign oxidation numbers to each element in the compound.

Oxidation number of sodium (Na)

Sodium is a group 1 element, and it always has an oxidation number of +1 in compounds.

Oxidation number of carbon (C)

Carbon is a group 4 element, and it usually has an oxidation number of -4 in compounds. However, in this compound, carbon is bonded to nitrogen and iron, which are more electronegative than carbon. Therefore, carbon has a partial positive charge, and its oxidation number is +3.

Oxidation number of nitrogen (N)

Nitrogen is a group 5 element, and it usually has an oxidation number of -3 in compounds. However, in this compound, nitrogen is bonded to iron and carbon, which are less electronegative than nitrogen. Therefore, nitrogen has a partial negative charge, and its oxidation number is -1.

Oxidation number of oxygen (O)

Oxygen is a group 6 element, and it usually has an oxidation number of -2 in compounds. However, there is no oxygen in this compound.

Oxidation number of iron (Fe)

To calculate the oxidation number of iron, we need to use the following equation:

Oxidation number of iron + (oxidation number of nitrogen x number of nitrogen atoms) + (oxidation number of carbon x number of carbon atoms) + (oxidation number of sodium x number of sodium atoms) = charge of the compound

Plugging in the values, we get:

Oxidation number of iron + (-1 x 1) + (+3 x 5) + (+1 x 2) = 0

Simplifying the equation, we get:

Oxidation number of iron = -3/5

Therefore, the oxidation number of iron in Na2[Fe(CN)5(NO )] is -3/5.

Conclusion

The oxidation number of iron in Na2[Fe(CN)5(NO )] is -3/5. This compound contains multiple ligands, including cyanide and nitrosyl, which can affect the oxidation state of the central metal ion. The oxidation state of iron in this compound is less than its maximum oxidation state (+3), indicating that it is in a reduced state.

+2+x-5+1=0x=+2