Why awe elementary reactions involving three or more reactants very uncommon?

A reaction is believed to occur by the following mechanism: Stepl: 2AI (Fast equilibrium) Step 2: I + B C (Slow) Overall: 2 A + B C What experimentally determined rate law would lead to this mechanism? (a) Rate = k[A][B] (b) Rate = k[A]2[B] (c) Rate = k[A]2 (d) Rate = k[I][B]

Ozone, O3, in the Earths upper atmosphere decomposes according to the equation 2 O3(g) 3 O2(g) The mechanism of the reaction is thought to proceed through an initial fast, reversible step followed by a slow, second step. Step 1: Fast, reversible O3(g) O2(g) + O(g) Step 2: Slow O3(g) + O(g) 2 O2(g) (a) Which of the steps is rate-determining? (b) Write the rate equation for the rate-determining step

The following statements relate to the reaction for the formation of HI: H2(g) + I2(g) 2 HI(g)Rate = k[H2][I2] Determine which of the following statements are true. If a statement is false, indicate why it is incorrect. (a) The reaction must occur in a single step. (b) This is a second-order reaction overall. (c) Raising the temperature will cause the value of k to decrease. (d) Raising the temperature lowers the activation energy for this reaction. (e) If the concentrations of both reactants are doubled, the rate will double. (f) Adding a catalyst in the reaction will cause the initial rate to increase.

The label on a bottle of 3% (by volume) hydrogen peroxide, H2O2, purchased at a grocery store, states that the solution should be stored in a cool, dark place. H2O2decomposes slowly over time, and the rate of decomposition increases with an increase in temperature and in the presence of light. However, the rate of decomposition increases dramatically if a small amount of powdered MnO- is added to the solution. The decomposition products are H2O and O2. MnO2 is not consumed in the reaction. Write the equation for the decomposition of H2O2. What role does MnO2 play? In the chemistry lab, a student substituted a chunk of MnO2 for the powdered compound. The reaction rate was not appreciably increased. WTiat is one possible explanation for this observation? Is MnO2 part of the stoichiometry of the decomposition of H2O2?

The reaction H2SeO3(aq) + 6I-(aq) + 4H+(aq) Se(s) + 2I-3(aq) + 3H2O(l) was studied at 0C, and the following data were obtained: [H2SeO3]0 (mol/L) [H+]0 (mol/L) [I]0(mol/L) Initial Rate (mol/L s) 1.0 104 2.0 102 2.0 102 1.66 107 2.0 104 2.0 102 2.0 10-2 3.33 107 3.0 104 2.0 102 2.0 102 4.99 107 1.0 104 4.0 102 2.0 102 6.66 107 1.0 104 1.0 102 2.0 102 0.42 107 1.0 104 2.0 102 4.0 102 13.2 107 1.0 104 1.0 102 4.0 102 3.36 107 These relationships hold only if there is a very small amount of I3 present. What is the rate law and the value of the rate constant? (Assumethatrate=[H2SeO3]t)

The rate constant, k, at 25 C is 0.27/h for the reaction Pt(NH3)2Cl2(aq) + H2O() [Pt(NH3)2(H2O)Cl]+(aq) + Cl(aq) and the rate equation is Reaction rate = k[Pt(NH3)2C12] Calculate the rate of reaction when the concentration of Pt(NH3)2Cl2 is 0.020 M.

Iodomethane (CH3I) is a commonly used reagent in organic chemistry. When used properly, this reagent allows chemists to introduce methyl groups in many different useful applications. The chemical does pose a risk as a carcinogen, possibly owing to iodomethanes ability to react with portions of the DNA strand (if they were to come in contact). Consider the following hypothetical initial rates data: [DNA]0 ( mol/L) [CH3I]0 ( mol/L) Initial Rate (mol/Ls) 0.100 0.100 3.20 104 0.100 0.200 6.40 104 0.200 0.200 1.28 103 Which of the following could be a possible mechanism to explain the initial rate data? MechanismIDNA+CH3IDNACH3++IMechanismIICH3ICH3++ISlowDNA+CH3+DNACH3+Fast

For the reaction of crystal violet with NaOH(aq), the measured rate of reaction is 1.27 106 mol L1 s1 when the concentration of crystal violet cation is 4.13 105 mol/L. (a) Estimate how long it will take for the concentration of crystal violet to drop from 4.30 105 mol/L to 3.96 105 mol/L. (b) Could you use the same method to make an accurate estimate of how long it would take for the concentration of crystal violet to drop from 4.30 105 mol/L to 0.43 105 mol/L? Explain why or why not.