A flask is filled with equal moles of A and B. The half lives of A and B are 100 s and 50 s respectively and are independent of the initial concentration. The time required for the concentration of A to be four times that of B is ___________ s.

(Given : ln 2 = 0.693)

At 345 K, the half life for the decomposition of a sample of a gaseous compound initially at 55.5 kPa was 340 s. When the pressure was 27.8 kPa, the half life was found to be 170 s. The order of the reaction is ____________. [integer answer]

For a given chemical reaction

$$\gamma$$₁A + $$\gamma$$₂B $$\to$$ $$\gamma$$₃C + $$\gamma$$₄D

Concentration of C changes from 10 mmol dm^$$-$$3 to 20 mmol dm^$$-$$3 in 10 seconds. Rate of appearance of D is 1.5 times the rate of disappearance of B which is twice the rate of disappearance A. The rate of appearance of D has been experimentally determined to be 9 mmol dm^$$-$$3 s^$$-$$1. Therefore, the rate of reaction is _____________ mmol dm^$$-$$3 s^$$-$$1. (Nearest Integer)

The rate constants for decomposition of acetaldehyde have been measured over the temperature range 700 - 1000 K. The data has been analysed by plotting ln k vs $${{{{10}^3}} \over T}$$ graph. The value of activation energy for the reaction is ___________ kJ mol^$$-$$1. (Nearest integer)

(Given : R = 8.31 J K^$$-$$1 mol^$$-$$1)