The first transition series metal 'M' has the highest enthalpy of atomisation in its series. One of its aquated ions ( Mn+) exists in green colour. The nature of the oxide formed by the above Mn+ ion is:
- basic
- neutral
- amphoteric
- acidic
Answer
(1) basic
Solution
As per NCERT, aH ( kJ mol-1) of 3d metals: Sc 326, Ti 473, V 515, Cr 397, Mn 281, Fe 416, Co 425, Ni 430, Cu 339, Zn 126.
Highest for vanadium M = V
V3+(aq) (3d2) is green Mn+ = V3+
Its oxide is V2O3. In a lower oxidation state the oxide of a transition metal is basic (V2O3 basic, V2O4 less basic, V2O5 amphoteric).
The oxide is basic.
Answer: (1)