(i) Name the element of 3d-transition series which shows maximum number of oxidation states. Why does it show so? (ii) Which transition metal of 3d-series has positive E^0(M^(2+)//M) value and why? (iii) Out of Cr^(3+) and Mn^(3+) which is a stronger oxidizing agent andhy? (iv) Name a member of the lanthanoid series which is well known to exhibit + 2 oxidation state. (v) Complete the following equaton: MnO_(4)^(-) + 8H^(+) + 5e^(-) to

(i) Name the element of 3d-transition series which shows maximum numbe

1.	(i) Name the element of 3d-transition series which shows maximum number of oxidation states. Why does it show so? (ii) Which transition metal of 3d-series has positive E^0(M^(2+)//M) value and why? (iii) Out of Cr^(3+) and Mn^(3+) which is a stronger oxidizing agent andhy? (iv) Name a member of the lanthanoid series which is well known to exhibit + 2 oxidation state. (v) Complete the following equaton: MnO_(4)^(-) + 8H^(+) + 5e^(-) to
Answer» Solution :(i) MN, because of presence of 5 unpaired electrons in 3d-subshell (ii) Cu, because ENTHALPY of atomization and ionisation enthalpy is not compensated by enthalpy. (iii) Mnt because `Mn^(2+)` is more STABLE due to its half filled (3d) configuration. (iv) `Eu^(2+) (Eu)` (v) `MnO_(4)^(-) + 8H^(+) + 5e^(-) + Mn^(2+) + 4H_2O`.