The vapour pressures of A and B at 25$$^\circ$$C are 90 mm Hg and 15 mm Hg respectively. If A and B are mixed such that the mole fraction of A in the mixture is 0.6, then the mole fraction of B in the vapour phase is x $$\times$$ 10^$$-$$1. The value of x is ___________. (Nearest integer)

4g equimolar mixture of NaOH and Na₂CO₃ contains x g of NaOH and y g of Na₂CO₃. The value of x is ____________ g. (Nearest integer)

When 0.15 g of an organic compound was analyzed using Carius method for estimation of bromine, 0.2397 g of AgBr was obtained. The percentage of bromine in the organic compound is ______________. (Nearest integer)

[Atomic mass : Silver = 108, Bromine = 80]

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

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]