A. Is independent of temperature
B. Varies with temperature
C. Depends on the nature of the reactants
D. Both B. and C.
Related Mcqs:
- 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 kg respectively. The effective rate constant (keff) is given by________________?
A. keff = k + kg
B. keff = (k+ kg)/2
C. keff = (kkg)1/2
D. 1/keff = 1/k + 1/kg - In a reversible reaction, a catalyst increases the rate of forward reaction__________________?
A. Only
B. To a greater extent than that of the backward reaction
C. And decreases that of the backward reaction
D. And the backward reaction equally - The conversion in a mixed reactor/accomplishing a reaction A → 3R is 50% when gaseous reactant ‘A’ is introduced at the rate of 1 litre/second and the leaving flow rate is 2 litres/second. The holding time for this operation is _______________ second?
A. 0.5
B. 1
C. 2
D. 3 - The rate controlling step for the heterogeneous irreversible catalytic reaction A(g) + B(g) → C(g) is the surface reaction of absorbed A with absorbed B to give adsorbed C. The rate expression for this reaction can then be written as (where, KA, KB and KC are the equilibrium constants and is the rate constant of the rate controlling step) ?
A. k KA pApB / (1 + KApA + KBpB)
B. k KAKB pApB / (1 + KApA + KBpB)
C. k KAKB pApB / (1 + KApA + KBpB + KCpC)
D. k KAKB pApB / (1 + KApA + KBpB + KCpC)2 - The heat of reaction__________________?
A. Depends on the pressure only
B. Depends on the mechanism of reaction only
C. Depends on both pressure and mechanism of reaction
D. Is independent of the mechanism of reaction - Molecularity of a reaction__________________?
A. Is always equal to the overall order of reaction
B. May not be equal to the order of reaction
C. Can’t have a fractional value
D. Both B. and C. - A second order liquid phase reaction, A → B, is carried out in a mixed flow reactor operated in semi batch mode (no exit stream). The reactant A at concentration CAF is fed to the reactor at a volumetric flow rate of F. The volume of the reacting mixture is V and the density of the liquid mixture is constant. The mass balance for A is_______________________?
A. d(VCA)/dt = -F (CAF – CA) – kCA2V
B. d(VCA)/dt = F (CAF – CA) – kCA2V
C. d(VCA)/dt = -FCA – kCA2V
D. d(VCA)/dt = FCAF – kCA2V - Second order consecutive irreversible reaction as shown in the bellow figure, were carried out in a constant volume isothermal batch reactor with different initial feed compositions. Reactor temperature was same in all the cases. In experiments where the ratio of concentration of B to that of A in the initial feed was less than 0.5, the concentration of B increased first, reached a maximum and then declined with time. However, for all experiments where this concentration ratio was 0.5 or above, concentration of B decreased monotonically with time right from the beginning. What is the ratio of the two rate constants (k1/k2) ?
A. 1/4
B. 1/2
C. 2
D. 4 - Rate constant for a first order reaction does not depend upon reaction time, extent of reaction and the initial concentration of reactants; but it is a function of reaction temperature. In a chemical reaction, the time required to reduce the concentration of reactant from 100 gm moles/litre to 50 gm moles/litre is same as that required to reduce it from 2 gm moles/litre to 1 gm mole/litre in the same volume. Then the order of this reaction is ?
A. 0
B. 1
C. 2
D. 3 - For a _____________ order reaction, the units of rate constant and rate of reaction are the same ?
A. Zero
B. First
C. Second
D. Fractional
