Consider the following cell reaction :

$$C{d_{(s)}} + H{g_2}S{O_{4(s)}} + {9 \over 5}{H_2}{O_{(l)}}$$ $$\rightleftharpoons$$ $$CdS{O_4}.{9 \over 5}{H_2}{O_{(s)}} + 2H{g_{(l)}}$$

The value of $$E_{cell}^0$$ is 4.315 V at 25$$^\circ$$C. If $$\Delta$$H$$^\circ$$ = $$-$$825.2 kJ mol^$$-$$1, the standard entropy change $$\Delta$$S$$^\circ$$ in J K^$$-$$1 is ___________. (Nearest integer) [Given : Faraday constant = 96487 C mol^$$-$$1]

The molarity of the solution prepared by dissolving 6.3 g of oxalic acid (H₂C₂O₄.2H₂O) in 250 mL of water in mol L^$$-$$1 is x $$\times$$ 10^$$-$$2. The value of x is _____________. (Nearest integer) [Atomic mass : H : 1.0, C : 12.0, O : 16.0]

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)