Read the passage given below and answer the following questions: Within the 3d series, manganese exhibits oxidation states in aqueous solution from +2 to +7, ranging from Mn^(2+)(aq) to MnO_(4)^(-) (aq). Likewise, iron forms both Fe^(2+)(aq) and Fe^(3+)(aq) as well as the FeO_(4)^(2-) ion. Cr and Mn form oxyions CrO_(4)^(2-) , MnO_(4)^(-) , owing to their willingness to form multiple bonds . The pattern with the early transition metals-in the 3d series up to Mn, and for the 4d, 5d metals up to Ru and Os—is that the maximum oxidation state corresponds to the number of ‘‘outer shell’’ electrons. The highest oxidation states of the 3d metals may depend upon complex formation (e.g., the stabilization of Co^(3+) by ammonia) or upon the pH (thus MnO_(4)^(2-) (aq) is prone to disproportionation in acidic solution). Within the 3d series, there is considerable variation in relative stability of oxidation states, sometimes on moving from one metal to a neighbor, thus, for iron, Fe^(3+) is more stable than Fe^(2+) , especially in alkaline conditions, while the reverse is true for cobalt. The ability of transition metals to exhibit a wide range of oxidation states is marked with metals such as vanadium, where the standard potentials can be rather small, making a switch between states relatively easy. (Cotton, S. A. (2011). Lanthanides: Comparison to 3d metals. Encyclopedia of inorganic and Bioinorganic Chemistry.) In the following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices on the basis of the above passage. Assertion: Fe^(3+) is more stable than Fe^(2+) Reason: Fe^(3+) has 3d^(5) configuration while Fe^(2+) has 3d^(6) configuration.
