KCET2016Chemistryd and f Block Elements
( M n²⁺ ) compounds are more stable than ( F e²⁺ ) compounds towards oxidation to their ( +3 ) state, because
Options
- A( M n²⁺ ) is more stable with high ( 3 r d ) lonisation energy.
- B( M n²⁺ ) is bigger in size.
- C( M n²⁺ ) has completely filled d-orbitals.
- D( M n²⁺ ) does not exist.
Correct answer
A. ( M n²⁺ ) is more stable with high ( 3 r d ) lonisation energy.
Step-by-step solution
Electronic configuration of ( M n²⁺ ) is ( 4 s⁰ 3 d⁵ ) : array |l|l|l|l|l| ( 1 ) & ( 1 ) & ( 1 ) & ( 1 ) & ( 1 ) array Electronic configuration of ( F e²⁺ ) is ( 4 s⁰ 3 d⁶: ) array |ll|l|l|l|l| ( 1 ) & ( ) & ( 1 ) & ( 1 ) & ( 1 ) & ( 1 ) array Since, in ( M n²⁺ ) the d-orbital is completely half-filled, therefore, its third ionization energy is high and hence, it stable towards oxidation to ( +3 ) oxidation states, whereas, in ( Fe ²⁺ ), the d-orbital is partially filled and only one electron is paired, therefore,