When 800 mL of 0.5 M nitric acid is heated in a beaker, its volume is reduced to half and 11.5 g of nitric acid is evaporated. The molarity of the remaining nitric acid solution is x $$\times$$ 10^$$-$$2 M. (Nearest integer)

(Molar mass of nitric acid is 63 g mol^$$-$$1)

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)

The amount of charge in $$\mathrm{F}$$ (Faraday) required to obtain one mole of iron from $$\mathrm{Fe}_{3} \mathrm{O}_{4}$$ is ___________. (Nearest Integer)

For a reaction $$\mathrm{A} \rightarrow 2 \mathrm{~B}+\mathrm{C}$$ the half lives are $$100 \mathrm{~s}$$ and $$50 \mathrm{~s}$$ when the concentration of reactant $$\mathrm{A}$$ is $$0.5$$ and $$1.0 \mathrm{~mol} \mathrm{~L}^{-1}$$ respectively. The order of the reaction is ______________ . (Nearest Integer)