Amount of oxalic acid present in a solution can be determined by its titration with $$KMn{O_4}$$ solution in the presence of $${H_2}S{O_4}.$$ The titration gives unsatisfactory result when carried out in the presence of $$HCl,$$ because $$HCl$$ :

Identify the incorrect statement among the following :

The actinoids exhibits more number of oxidation states in general than the lanthanoids. This is because :

The “spin-only” magnetic moment [in units of Bohr magneton, (µ_B)] of Ni²⁺ in aqueous solution would be : (Atomic number of Ni = 28)