Which transition metal reduces steam to evolve hydrogen?

Which is the most reactive metal among the given options?

All $Cu(II)$ halides are known except $CuI_2$,because ....

Iodine is formed when $KI$ reacts with a solution of

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 addition of dilute $NaOH$ to $Cr^{3+}$ salt solution will give: