Chemistry

A proposed mechanism for destruction of ozone gas in the stratosphere is represented above. Which of the follow is evidence that the mechanism is occuring? A. The presence of CL(g) increases the rate of the overall reaction. B. The presence of Cl(g) decreases the rate of the overall reaction. C. The presence of Cl(g) increases the equilibrium constant of the overall reaction. D. The presence of Cl(g) decreases the equilibrium constant of the overall reaction.

A. The presence of CL(g) increases the rate of the overall reaction.

Which of the following rate laws for the overall reaction correpsonds to the proposed mechanism? A- Rate=k[03]^2 B- Rate=k[Cl][03] C- Rate=k[ClO][O3]^2

B- Rate=k[Cl][03]

Which of the following reaction energy profiles corresponds to the propsed mechanis,. A. B. C. D

B.

What is the following chemical species in most lieklty to decompose )3 in the upper atmosphere through the mechanism above. A. HE B. Br C. N2 D. O2

B. Br

Consider the reaction represented by the equation 2x + 2Z -> X2Z2. During a reaction in which a large excess of reaction X was present the concentration of reacant Z was monitored over time. A plot of the natural logarithm of the concentration of Z verus time is shown in the figure above. The order of the reaction with respect to reactant Z is. A. zero order B. first order c. second order d. third order.

B. First order

A sample of K2O3 was placed in an evacuated container, and the reaction represented above occurred. The value of PN2O3, the partial pressure of N2O3 was measured during the reaction and recored in the table below. Which of the following correctly describes the reaction? A The decomposition of N2O3 is zero-order reaction. B The decompostition of N2O3 is an first order reaction. C The decomposition of N2O3 is a second-order reaction. D The Overall reaction order is 3.

B. The decomposition of N2O3 is a first order reaction.

The reaction represented above occurs in a single step that involves the collisions between a particl of NO and a particle of NO3. A scientist correctly calculates the rate of the colluisons between NO and NO# that have sufficient energy toover the activation energy. THe observed reaction rate is only a small fraction of the calculated collision rate. Which of the following best explains the disrepancy. A. The energy of collisions between two reactant particles is frequently absorbed by collision with a third particle. B. Two reactant particles most collide with a particular orientation in order to react. C. The activation energy for a reaction is dependant on the concentrations of the particles of the reactants. D. The activation energy for a reaction is dependeny on the temparture.

B. Two reactant particles most collide with a particular orientation in order to react.

A reaction and its experimentally determined rate law are represented above, possible mechanisms for the reaction are give below. A. Only mechanism 1 is consistent with the rate law. B. Only mechanism 2 is consistent with the rate law. C. Both mech 1 and mech 2 are consistent with the rate law. D. Niether mechanism 1 nor mechanism 2 is consistent with the rate law.

C. Both mech 1 and mech 2 are consistent with the rate law.

A kinetics experiment is set up to collect the gas that is generated when a sample of chalk consiting of primarily solid CaCO3, is added to a solution of ethanoic acid, CH3COOH. The rate of the reaction betwee CaCO3 and CH3COOH is determined by measuring the volume of gas generated at 25C and 1 atm as a function of time. Which of the following experimental conditions is most likely to increase the rate of gas production. A. Decreasing the volume of ethanoic acid solution used in the experiment. B. Decreasing the concentrationof the ethanol acid solution used in the experiemnt C Decreasing the temperature at which the experiment is performed. D. Decreasing the particle size of CaCO2 grinding it into a fine powder.

D. Decreasing the particle size of CaCO2 grinding it into a fine powder.

2NO -> N2O3 N2O3 + O2 -> 2NO2 Which of the following statements are true? A. Step 1 represents a unimolecular reaction. B. Increasing the concentration of NO will decrease the overall rate of the reaction. C. Raising the temperature will have no effect on the numerical value of the rate constant. D. The rate law that is consistent with the mechanism is rate =k[NO]2[o2]

D. The rate law that is consistent with the mechanism is rate =k[NO]2[o2]