OChem Qs MCAT

) Calculate the activation energy for vacancy formation in aluminium, given that the equilibriumnumber of vacancies at 500°C (773 K) is 7.55 × 1023 m−3. The atomic weight and density (at500°C) for aluminium are, respectively, 26.98 g/mol and 2.62 g/cm3. (

In the absence of a catalyst, the rate constant for the overall reaction is on the order of k(298 K) ~ 10–26 M–1. The catalyzed reaction has a rate constant on the order of k(298 K) ~ 107 M–1 (step 1 is the rate determining step).   Would you expect CO to be significantly oxidized in the absence of a catalyst? Is the uncatalyzed process thermodynamically limited, or kinetically limited? Explain your answer.

(d) Consider the reaction: [Co(NH3)5(H₂O)]³+ + X¯ → [Co(NH3)5X]²+ + H₂O (i) Is this an electron transfer or a substitution reaction? Justify your answer. (ii) The reaction rate changes by less than a factor of 2 when X-is varied among Cl, Br, N3, and SCN. What does this observation say about the reaction mechanism?

(c) At low temperatures, reaction (3) is replaced by the following reaction forming a stable dimer of CIO, which itself is rapidly photolysed to form Cl atoms: CIO + CIO Cl₂O2 2C1 + O2 Describe briefly, in qualitative terms, the effect that this reaction will have on the observed rate of ozone destruction. Note that Ka[Cl2] is the rate at which photons are absorbed by Cl2, and is often referred to as la.

E17C.1(b) The equilibrium constant for the binding of a drug molecule to a protein was measured as 200. In a separate experiment, the rate constant for the binding process, which is second order overall, was found to be 1.5 x 10 dm mol s. What is the rate constant for the first-order dissociation of the drug molecule from the protein- drug complex?

. In the photobromination of cinnamic acid, using radiation at 420 nm with an intensity of 1.4 x 10 3 Js" and 70% light absorption in a liter of solution for a period of 15 min the concentration of Br, decreased by 0.075 mol.L:1 during this period. What is the quantum yield of the product formation?

write the correct rate law expression for the reaction.

The overall reaction of hydroxide radical with hydrogen gas occurs as follows: OH'g) + H,(g) – H0(g) + H'(g) Part A This reaction plays a significant role in the chemistry of the earth's atmosphere by eventually converting OH to HO, through the subsequent reaction of H with O,. HO, is involved in the destruction of stratospheric ozone (J. Phys. Chem. A, 2006, 110, 6978). Determine the activation energy for the reaction of OH with H, reaction. The rate constants for the reaction of OH with H, were found to be 5.54x10 L mol s at 36. C and 1.09x10 L molrs at -27. °C. -20.9 kJ mol1 O 18.3 kJ mol1 O 25.1 kJ mol O -18.3 kJ mol O 25.1 kJ mol

answer all parts please

The overall reaction of hydroxide radical with hydrogen gas occurs as follows: OH (g) + H2(g) – H20(g) + H'(g) Part A This reaction plays a significant role in the chemistry of the earth's atmosphere by eventually converting OH to HO, through the subsequent reaction of H with O2. HO2 is involved in the destruction of stratospheric ozone (J. Phys. Chem. A, 2006, 110. 6978). Determine the activation energy for the reaction of OH with H, reaction. O 16.4 kJ mol The rate constants for the reaction of OH with H2 were found to be 1.83x10' L mol s'at 107. °C and 5.68×10° L mol's at 37. C. -1 O -85.9 kJ mol -1 O -16.4 kJ mol O 54.8 kJ mol O 65.9 kJ mol

Can “conventional” physical chemistry, such as the study of kinetics, thermodynamics, spectroscopy and electrochemistry, be regarded as a kind of computational chemistry

2. From the perspective of thermodynamics, the total free energy change of antibody (Ab) and antigen (Ag) interaction can be expressed as AG = -RTln(K·1M), where R = 8.3145 J/(mol·K) is the gas constant, T is the temperature in the unit of Kelvin (K = °C + 273.15), and K is affinity constant of Ab-Ag interaction. Note: 1M here means 1 Molar, so that affinity constant K has the unit of 1/M. A negative value of free energy change AG indicates energy release, while a positive value of free energy change AG indicates energy absorption. a) At body temperature T = 37°C, if we know the affinity constant K = 108/M, please compute the total free energy change AG. b) The presence of a single charged group on epitope or antigenic determinant of an antigen, typically increases the energy release by 20 kJ/mol for Ab-Ag interaction. Please compute the

The free energy change, AG, in the homogenous cross-exchange ET reaction of [Ru(bpy)2]* and ferricytochrome c is -104.6 kJ mol¯1. The second-order activation-limited rate constant, kobs, is 2.5 × 108 M-1 s-1. Taking KDA = 1.0 M¹, N = 1 × 1011 s-1, and x = 1, estimate the values of AG* and 2. In what kinetic region is this reaction? Hint: By substituting the Marcus equation into the expression for the rate constant of an adiabatic homogenous ET reaction, the rate constant of a cross-exchange ET reaction may be written as (AG+2)² Ket = KVN exp - 4λRT and, by rearrangement, In Ket KV 1 (AG+ 2)² 1 AG2 1 AG == + constant 42 RT 42 RT 2 RT

Use the References to access important values if needed for this question. For the gas phase isomerization of methyl cis-cinnamate, cis-C6H5 CH=CHCOOCH3 → trans-C6H5 CH=CHCOOCH3 the rate constant at 669 K is 9.12 x 10-4 s and the rate constant at 711 Kis 5.79 x 107 s-¹. -3 The activation energy for the gas phase isomerization of methyl cis-cinnamate is kJ.

The data below apply to the reaction, (CH3)3CBr + H2O → (CH3)3COH + HBr. t/h 0 3.15 6.20 10.00 18.30 30.80 [(CH3)3CBr]/10−2 mol·dm−3 10.39 8.96 7.76 6.39 3.53 2.07 Identify the order of the reaction of (CH3)3CBr. Calculate the rate constant of (CH3)3CBr.  Calculate the molar concentration of (CH3)3CBr remaining after 43.8 h.

Use the equation:  ln(k1/k2)=−Ea/R(1/T1−1/T2)  to calculate the activation energy k1 is 0.00316 k2 is 0.0106 R is 8.314 T2 is 298  T1 is 273

You may want to reference (Pages 245-246) Section 7.8 while completing this problem. 3 E Course Home. Calcium cyanamide reacts with water to form calcium carbonate and ammonia via the following reaction: CaCN2 (s) + 3H₂O(1)→ CaCO3(s) + 2NH3(g) 80 F3 $ 4 000 000 F4 % 5 M MasteringChemistry: Homework Chapter 7 F5 openvellum.ecollege.com ^ 6 ▼ Part A F6 How many grams of water are needed to react with 71.0 g CaCN₂? mass H₂O = Submit Previous Answers Request Answer Part B X Incorrect; Try Again; 5 attempts remaining mass NH3 = IVE ΑΣΦ How many grams of NH3 are produced from 5.22 g CaCN₂? MacBook Air b Answered: Attempt 1 ed with Feedback w.. Submit Previous Answers Request Answer X Incorrect; Try Again; 5 attempts remaining & 7 [ΨΕ ΑΣΦ Copyright © 2022 Pearson Education Inc. All rights reserved. | Terms of Use | Privacy Policy | Permissions Contact Us | P Pearson Ad F7 * 8 ∞ DII F8 Swed ( 9 F9 ? ? g ) 0 g 21 Shopping Ba Review | Constants F10 () F11