At $$298 \mathrm{~K}$$, the equilibrium constant is $$2 \times 10^{15}$$ for the reaction :

$$\mathrm{Cu}(\mathrm{s})+2 \mathrm{Ag}^{+}(\mathrm{aq}) \rightleftharpoons \mathrm{Cu}^{2+}(\mathrm{aq})+2 \mathrm{Ag}(\mathrm{s})$$

The equilibrium constant for the reaction

$$ \frac{1}{2} \mathrm{Cu}^{2+}(\mathrm{aq})+\mathrm{Ag}(\mathrm{s}) \rightleftharpoons \frac{1}{2} \mathrm{Cu}(\mathrm{s})+\mathrm{Ag}^{+}(\mathrm{aq}) $$

is $$x \times 10^{-8}$$. The value of $$x$$ is _____________. (Nearest Integer)

2NOCl(g) $$\rightleftharpoons$$ 2NO(g) + Cl₂(g)

In an experiment, 2.0 moles of NOCl was placed in a one-litre flask and the concentration of NO after equilibrium established, was found to be 0.4 mol/L. The equilibrium constant at 30$$^\circ$$C is ______________ $$\times$$ 10^$$-$$4.

40% of HI undergoes decomposition to H₂ and I₂ at 300 K. $$\Delta$$G$$^\Theta $$ for this decomposition reaction at one atmosphere pressure is __________ J mol^$$-$$1. [nearest integer]

(Use R = 8.31 J K^$$-$$1 mol^$$-$$1 ; log 2 = 0.3010, ln 10 = 2.3, log 3 = 0.477)

50 mL of 0.1 M CH₃COOH is being titrated against 0.1 M NaOH. When 25 mL of NaOH has been added, the pH of the solution will be _____________ $$\times$$ 10^$$-$$2. (Nearest integer)

(Given : pK_a (CH₃COOH) = 4.76)

log 2 = 0.30

log 3 = 0.48

log 5 = 0.69

log 7 = 0.84

log 11 = 1.04