The Arrhenius equation is k = A*e -\Delta G Î G â¡/RT in units of sec-1. Letâs assume A= 1 and RT = 1. The NEW Arrhenius equation is k = e -\Delta G Î G â¡ (also in units of sec-1). For the uncatalyzed reaction (A -> P), the free energy barrier is \Delta G Î G â¡ = 5. Fraction of total product at time t = 1 - e-kt Now you add a catalyst which breaks this reaction down into 2 steps A -> B -> P with free energy barriers\Delta G Î G â¡1 = 3 and \Delta G Î G â¡2 = 2 (rate for step 1 (AB) is k1, rate for step 2 (BP) is k2). Fraction of total product at time t = 1- [ ( k2e-k1*t â k1e-k2*t ) / (k2-k1) ] What fraction of A is P after t=5 seconds in the uncatalyzed case? (PU) What fraction of A is P after t=5 seconds in the catalyzed case? (PC) How many times faster is catalyzed versus uncatalyzed? PC/PU (This will be your answer to this question) Use at least 2 decimal places
The Arrhenius equation is k = A*e -\Delta G Î G â¡/RT in units of sec-1. Letâs assume A= 1 and RT = 1. The NEW Arrhenius equation is k = e -\Delta G Î G â¡ (also in units of sec-1). For the uncatalyzed reaction (A -> P), the free energy barrier is \Delta G Î G â¡ = 5. Fraction of total product at time t = 1 - e-kt Now you add a catalyst which breaks this reaction down into 2 steps A -> B -> P with free energy barriers\Delta G Î G â¡1 = 3 and \Delta G Î G â¡2 = 2 (rate for step 1 (AB) is k1, rate for step 2 (BP) is k2). Fraction of total product at time t = 1- [ ( k2e-k1*t â k1e-k2*t ) / (k2-k1) ] What fraction of A is P after t=5 seconds in the uncatalyzed case? (PU) What fraction of A is P after t=5 seconds in the catalyzed case? (PC) How many times faster is catalyzed versus uncatalyzed? PC/PU (This will be your answer to this question) Use at least 2 decimal places
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Related questions
Results:
Slope 1 | 2 | 3 | 4 |
0.25516 kPa | 0.09496 kPa | 0.010285 kPa | .69419 kPa |
20.9 C | 20.9 | 20.9 | 34.2 C |
The following mechanism has been proposed for this reaction:
H2O2 + I- ---> IO-+ H2O (step 1, rate determining)
H2O2 + IO----> I- + H2O + O2 (step 2)
1. Identify any intermediate species and/or catalyst species in this mechanism.
2. What is the exact (not general) rate expression for the catalyzed reaction? Does your data from runs 1 â 3 support the rate expression? Explain.
3. Calculate the rate constant, k, at room temperature (average value) and room temperature + 10 °C. Hint: change your rate units into mol/L·s (using PV = nRT).
4. Determine the activation energy for the catalyzed reaction in kJ/mol using the two-point Arrhenius equation.
5. Do you expect the activation energy of the uncatalyzed reaction to be larger, smaller, or the same as the catalyzed reaction? Explain.