A. 1.6
B. 2
C. 2.24
D. 2.5
Related Mcqs:
- The rate expression for a heterogeneous catalytic reaction is given by, – rA = K.KA PA(1 + KA.PA + KR.PR), where K is surface reaction rate constant and KA and KR are absorption equilibrium constants of A and R respectively. If KR PR >> (1 + KA PA), the apparent activation energy EA is equal to (given E is the activation energy for the reaction and ΔHR and ΔHA are the activation energies of adsorption of R and A) ?
A. E
B. E + ΔHA
C. E + ΔHA – ΔHR)
D. ΔHA + ΔHR - The rate constant of a chemical reaction increases by 100 times when the temperature is increased from 400 °K to 500 °K. Assuming transition state theory is valid, the value of „E/R’ is __________________?
A. 8987°K
B. 9210°K
C. 8764°K
D. 8621°K - 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 - The temperature dependence of reaction rate constant (K) by Arrhenius law is given by_______________?
A. K α e-E/RT
B. K α eE/RT
C. K α T . e-E/RT
D. K α √T . e-E/RT - 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 minimum energy required to allow a chemical reaction to proceed is termed as the ‘threshold energy ‘. Chemical reactions with low activation energy are ________________?
A. Always irreversible
B. Insensitive to temperature changes
C. Mostly irreversible
D. Highly temperature sensitive - In a reaction, the threshold energy is equal to (where, A = activation energy N = normal energy of reactants) ?
A. A
B. N
C. A + N
D. A – N - The rate of the heterogeneous catalytic reaction A(g) + B(g) → C(g) is given by -rA = k.KA.pA.PB/(1 + KA.PA + Kc.pc), where KA and Kc are the adsorption equilibrium constants. The rate controlling step for this reaction is_______________?
A. Absorption of A
B. Surface reaction between absorbed A and absorbed B
C. Surface reaction between absorbed A and B in the gas phase
D. Surface reaction between A in the gas phase and absorbed B - Transition state theory gives the rate constant as__________________?
A. K α e-E/RT
B. K α eE/RT
C. K α T . e-E/RT
D. K α √T . e-E/RT - According to Arrhenius equation of temperature dependency of rate constant for an elementary reaction _________________?
A. k ∝ √T
B. k ∝ e-E/RT
C. k ∝ T e-E/RT
D. None of these
