The number of correct statements from the following is ___________.

A. For $$1 \mathrm{s}$$ orbital, the probability density is maximum at the nucleus

B. For $$2 \mathrm{s}$$ orbital, the probability density first increases to maximum and then decreases sharply to zero.

C. Boundary surface diagrams of the orbitals encloses a region of $$100 \%$$ probability of finding the electron.

D. p and d-orbitals have 1 and 2 angular nodes respectively.

E. probability density of p-orbital is zero at the nucleus

4.5 moles each of hydrogen and iodine is heated in a sealed ten litre vessel. At equilibrium, 3 moles of $$\mathrm{HI}$$ were found. The equilibrium constant for $$\mathrm{H}_{2}(\mathrm{~g})+\mathrm{I}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{HI}(\mathrm{g})$$ is _________.

The number of correct statements from the following is __________

A. $$\mathrm{E_{\text {cell }}}$$ is an intensive parameter

B. A negative $$\mathrm{E}^{\ominus}$$ means that the redox couple is a stronger reducing agent than the $$\mathrm{H}^{+} / \mathrm{H}_{2}$$ couple.

C. The amount of electricity required for oxidation or reduction depends on the stoichiometry of the electrode reaction.

D. The amount of chemical reaction which occurs at any electrode during electrolysis by a current is proportional to the quantity of electricity passed through the electrolyte.

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 $$24 \mathrm{~g} \mathrm{~mol}^{-1}$$