The total number of reagents from those given blow, that can convert nitrobenzene into aniline is ___________. (Integer answer)

I. Sn $$-$$ HCl

II. Sn $$-$$ NH₄OH

III. Fe $$-$$ HCl

IV. Zn $$-$$ HCl

V. H₂ $$-$$ Pd

VI. H₂ $$-$$ Raney Nickel

For a first order reaction, the ratio of the time for 75% completion of a reaction to the time for 50% completion is ____________. (Integer answer)

The number of hydrogen bonded water molecule(s) associated with stoichiometry CuSO₄.5H₂O is ____________.

According to the following figure, the magnitude of the enthalpy change of the reaction

A + B $$\to$$ M + N in kJ mol^$$-$$ is equal to ___________. (Integer answer)