The number of correct statements about modern adsorption theory of heterogeneous catalysis from the following is __________
A. The catalyst is diffused over the surface of reactants.
B. Reactants are adsorbed on the surface of the catalyst.
C. Occurrence of chemical reaction on the catalyst's surface through formation of an intermediate.
D. It is a combination of intermediate compound formation theory and the old adsorption theory.
E. It explains the action of the catalyst as well as those of catalytic promoters and poisons.
$$\mathrm{Mg}\left(\mathrm{NO}_{3}\right)_{2} \cdot \mathrm{XH}_{2} \mathrm{O}$$ and $$\mathrm{Ba}\left(\mathrm{NO}_{3}\right)_{2} \cdot \mathrm{YH}_{2} \mathrm{O}$$, represent formula of the crystalline forms of nitrate salts. Sum of $$\mathrm{X}$$ and $$\mathrm{Y}$$ is _____________.
The volume of hydrogen liberated at STP by treating $$2.4 \mathrm{~g}$$ of magnesium with excess of hydrochloric acid is _________ $$\times ~10^{-2} \mathrm{~L}$$
Given : Molar volume of gas is $$22.4 \mathrm{~L}$$ at STP.
Molar mass of magnesium is $$24 \mathrm{~g} \mathrm{~mol}^{-1}$$
If the radius of the largest circle with centre (2,0) inscribed in the ellipse $$x^2+4y^2=36$$ is r, then 12r$$^2$$ is equal to :