For the first order reaction A $$\to$$ 2B, 1 mole of reactant A gives 0.2 moles of B after 100 minutes. The half life of the reaction is __________ min. (Round off to the nearest integer).

[Use : ln 2 = 0.69, ln 10 = 2.3]

Properties of logarithms : ln x^y = y ln x;

$$\ln \left( {{x \over y}} \right) = \ln x - \ln y$$

(Round off to the nearest integer)

For a chemical reaction A $$\to$$ B, it was found that concentration of B is increased by 0.2 mol L^$$-$$ in 30 min. The average rate of the reaction is ____________ $$\times$$ 10^$$-$$1 mol L^$$-$$1 h^$$-$$1. (in nearest integer)

$${N_2}{O_{5(g)}} \to 2N{O_{2(g)}} + {1 \over 2}{O_{2(g)}}$$

In the above first order reaction the initial concentration of N₂O₅ is 2.40 $$\times$$ 10^$$-$$2 mol L^$$-$$1 at 318 K. The concentration of N₂O₅ after 1 hour was 1.60 $$\times$$ 10^$$-$$2 mol L^$$-$$1. The rate constant of the reaction at 318 K is ______________ $$\times$$ 10^$$-$$3 min^$$-$$1. (Nearest integer)

[Given : log 3 = 0.477, log 5 = 0.699]

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

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]