$$PC{l_5}(g) \to PC{l_3}(g) + C{l_2}(g)$$

In the above first order reaction the concentration of PCl₅ reduces from initial concentration 50 mol L^$$-$$1 to 10 mol L^$$-$$1 in 120 minutes at 300 K. The rate constant for the reaction at 300 K is x $$\times$$ 10^$$-$$2 min^$$-$$1. The value of x is __________. [Given log5 = 0.6989]

An aqueous solution of NiCl₂ was heated with excess sodium cyanide in presence of strong oxidizing agent to form [Ni(CN)₆]^2$$-$$. The total change in number of unpaired electrons on metal centre is _______________.

Potassium chlorate is prepared by electrolysis of KCl in basic solution as shown by following equation.

6OH^$$-$$ + Cl^$$-$$ $$\to$$ ClO₃^$$-$$ + 3H₂O + 6e^$$-$$

A current of xA has to be passed for 10h to produce 10.0g of potassium chlorate. The value of x is ____________. (Nearest integer)

(Molar mass of KClO₃ = 122.6 g mol^$$-$$1, F = 96500 C)

The value of $$\tan \left( {2{{\tan }^{ - 1}}\left( {{3 \over 5}} \right) + {{\sin }^{ - 1}}\left( {{5 \over {13}}} \right)} \right)$$ is equal to :