Given below are certain cations. Using inorganic qualitative analysis, arrange them in increasing group number from 0 to $$\mathrm{VI}$$.

A. $$\mathrm{Al}^{3+}$$

B. $$\mathrm{Cu}^{2+}$$

C. $$\mathrm{Ba}^{2+}$$

D. $$\mathrm{Co}^{2+}$$

E. $$\mathrm{Mg}^{2+}$$

Choose the correct answer from the options given below.

The work done during reversible isothermal expansion of one mole of hydrogen gas at $$25^{\circ} \mathrm{C}$$ from pressure of 20 atmosphere to 10 atmosphere is (Given $$\mathrm{R}=2.0 \mathrm{~cal} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$$)

Consider the following reaction in a sealed vessel at equilibrium with concentrations of $$\mathrm{N}_2=3.0 \times 10^{-3} \mathrm{M}, \mathrm{O}_2=4.2 \times 10^{-3} \mathrm{M}$$ and $$\mathrm{NO}=2.8 \times 10^{-3} \mathrm{M}$$.

$$2 \mathrm{NO}_{(\mathrm{g})} \rightleftharpoons \mathrm{N}_{2(\mathrm{~g})}+\mathrm{O}_{2(\mathrm{~g})}$$

If $$0.1 \mathrm{~mol} \mathrm{~L} \mathrm{~L}^{-1}$$ of $$\mathrm{NO}_{(\mathrm{g})}$$ is taken in a closed vessel, what will be degree of dissociation ($$\alpha$$) of $$\mathrm{NO}_{(\mathrm{g})}$$ at equilibrium?

A compound X contains $$32 \%$$ of A, $$20 \%$$ of B and remaining percentage of C. Then, the empirical formula of $$\mathrm{X}$$ is :

(Given atomic masses of A=64 ; B=40 ; C=32 u)