A pollutant P degrades according to first order kinetics. An aqueous stream containing P at 2 kmole/m³ and volumetric flow rate 1 m³/h requires a mixed flow reactor of volume V to bring down the pollutant level to 0.5 kmole/m³. The inlet concentration of the pollutant is now doubled and the volumetric flow rate is tripled. If the pollutant level is to be brought down to the same level of 0.5 kmole/m³, the volume of the mixed flow reactor should be increased by a factor of

A first order gaseous phase reaction is catalysed by a non-porous solid. The kinetic rate constant and the external mass transfer co-efficients are k and $${{\text{k}}_{\text{g}}}$$ respectively. The effective rate constant (k_eff) is given by

A. $${{\text{k}}_{\text{e}}}{\text{ff}} = {\text{k}} + {{\text{k}}_{\text{g}}}$$

B. $${{\text{k}}_{\text{e}}}{\text{ff}} = \frac{{{\text{k}} + {{\text{k}}_{\text{g}}}}}{2}$$

C. $${{\text{k}}_{\text{e}}}{\text{ff}} = {\left( {{\text{k}}{{\text{k}}_{\text{g}}}} \right)^{\frac{1}{2}}}$$

D. $$\frac{1}{{{{\text{k}}_{\text{e}}}{\text{ff}}}} = \frac{1}{{\text{k}}} + \frac{1}{{{{\text{k}}_{\text{g}}}}}$$

The half life period of a first order reaction is given by (where, K = rate constant. )

A. 1.5 K

B. 2.5 K

C. $$\frac{{0.693}}{{\text{K}}}$$

D. 6.93 K

Catalyst is a substance, which __________ chemical reaction.

A. Increases the speed of a

B. Decreases the speed of a

C. Can either increase or decrease the speed of a

D. Alters the value of equilibrium constant in a reversible

A chemical reaction is of zero order, when the reaction rate is (where, CA = concentration of reactant)

A. $$ \propto {\text{CA}}$$

B. $$ \propto \frac{1}{{{\text{CA}}}}$$

C. Independent of temperature

D. None of these