Question

Give reasons for the following: 

(i) Transition metals for large number of complex compounds 

(ii) Iron has higher enthalpy of atomisation that of copper 

(iii) Mn²⁺ compounds are more stable than Fe²⁺ compounds towards oxidation to +3 state

Answer 1

(I) Transition metals form a large number of compounds due to: 

(a) Comparatively small size 

(b) High ionic charges 

(c) Availability of d-orbitals 

(ii) Iron has great number of unpaired electrons than copper, hence higher the enthalpy of atomisation. 

(iii) The electronic configuration of Mn²⁺ is 3d⁵ which is stable. In Fe²⁺ the configuration is 3d⁶ , it can lose an electron easily to give stable 3d⁵ configuration.