For which of the following is the $E^{\ominus}(M^{3+} / M^{2+})$ value negative?

Which of the following is not amphoteric?

Which of the following compounds reacts with $NaOH$ and $Na_2O_2$ to produce a yellow color?

Which of the following metals becomes passive when treated with concentrated $HNO_3$?

Given below are two statements for catalytic properties of transition metals. Statement $I$: First row transition metals which act as catalyst utilise their $3d$ electrons only for formation of bonds between reactant molecules and atoms on the surface of catalyst. Statement $II$: There is increase in the concentration of reactants on the surface of catalyst which strengthens the bonds in reacting molecules. In the light of the above statements,choose the correct answer from the options given below:

The order of basic character for the monoxides of transition metals is . . . . .