The osmotic pressure of a dilute solution of an ionic compound XY in water is four times that of a solution of 0.01 M BaCl₂ in water. Assuming complete dissociation of the given ionic compounds in water, the concentration of XY (in mol L^–1) in solution is :

For a reaction,
N₂(g) + 3H₂(g) $$ \to $$ 2NH₃(g) ;
identify dihydrogen (H₂) as a limiting reagent in the following reaction mixtures.

The element having greatest difference between its first and second ionization energies, is :

The major product of the following reaction is :
$${\rm{C}}{{\rm{H}}_3}{\rm{CH = CHC}}{{\rm{O}}_2}{\rm{CH_3 }}\buildrel {LiAl{H_4}} \over \longrightarrow $$