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Chapter 13
Chemical Kinetics
| Question | Answer |
|---|---|
| Identify the methods used to monitor a reaction as it occurs in the reaction flask | Polarimeter Scetrometer Pressure measurement |
| Give the charateristics of the first order reaction having only one reactant | The fate of the reaction is directly proportional to the concentration of the reactant |
| Give the charateristics of a zero orcer reaction haing only one reactant | The rate of the reaction is not proportional to the concentration of the reactant |
| Give the charateristics of a second order reaction having only one reactant | The rate of the reaction is proportional to the square of the concentration of the reactant |
| What are the units for K in Rate= k[X][Y]^2? | 1/M^2s |
| What are the units for K in Rate= k[X]^2[Y]^2? | 1/M^3s |
| What are the units for K in Rate= k[X][Y]? | 1/Ms |
| What are the units for K in Rate= k[X] and k[X]^0[Y]^0? | 1/s |
| What are the units for K in Rate= k[X][Y]^1/2? | M-1/2s-1 |
| What are the units for K in Rate= k[X]^2? | M-1s-1 |
| Which of the following represents the integrated rate law for a first-order reaction? | ln[A]t/[A]o= -kt |
| Which of the following represents the integrated rate law for a second-order reaction? | 1/[A]t 1/[A]o= kt |
| Which of the following represents the integrated rate law for the zeroth-order reaction? | [A]t-[A]o= -kt |
| What data should be ploteed to show that experimental concentraction data fits a second-order reaction? | ln[reactant] vs. time |
| What data should be plotted to show that experimental concentration data fits a zeroth-order reaction? | [reactant]vs. time |
| Which of the following statements is FALSE? | The half life of a first order reaction is dependent on initial concentraion of reactant The half life of a sencond order reaction is not dependent on concentraion |
| Derive an expression for a '1/3-life' for a first-order reaction? | 1.099/k |
| Derive an expression for a '1/4-life' for a first-order reaction? | 1.386/k |
| For a reaction, what generally happens if the temp is increased? | an increase in k occurs, which results in a faster rate |
| Identify the rate-determining step. | the slowest step |
| Rate constants | are temp dependent |
| Identify an homogenous catalyst. | H2SO4 w/ concentrated HCl |
| Identify an heterogenous catalyst | Pd in H2 gas |
| In the hydrogenation of double bonds, a catalyst is needed. In the last step, the reactant must escape from the surface into the gas phase. This step is known as | Desorption |
| Biological catalysts that increase the rates of biochemical reactions are known as | enzymes |
| What are the units of k in a zero order reaction? | M/s |
| what are the units of k in a first order reaction? | 1/s |
| What are the units of k in a second order reaction? | M-1s-1 |
| Given the law Rate= k[X][Y]^2, how does the rate of reaction change if the concentration of Y is doubled? | The rate of reaction will increase by a factor of 4 |
| Give the law Rate= k[X][Y]^2, how does that rate of reaction change if the contration of X is doubled? | The rate of reaction will increase by a factor of 2 |
| Given the law Rate= [X][Y], how does the rate of reaction change if the concentration of Y is doubled? | The rate of reaction will increase by a factor two |
| Given the law Rate= k[X]^2[Y]^3, how does the rate of reaction change if the concentration of Y is doubled? | The rate of reaction will increase by a factor of 8 |
| Rate= k[A][B]^2, what will happen to the rate of reaction if the concentration of A is increased by a factor of 5.0? the rate will | increase by a factor of 5.00 |
| Rate= k[A][B]^2, what will happen to the rate of reaction if the concentration of B is increased by a factor of 3.00? the rate will | increase by a factor of 9.00 |
| What is the overall reaction order for the reaction that has the rate law: Rate= k[O2][NO]^2? | third order |
| Given the law Rate= k[X]^2[Y]^3, how does the rate of reaction change if the concentration of X is doubled? | The rate of reaction will increase by a factor of four |
| Which of the following represents the equation for a first-order half-life? | t 1/2= 0.693/k |
| Which of the following represents the equation for a second-order half-life? | t 1/2= [A]o/2k |
| Which of the following represents the equaton for a zero-order half-life? | t 1/2= [A]o/2k |
| Which of the following reactions would you predict to have the smallest orientation factor? | NOCl2 + NO --> 2 NOCl |
| Which of the following reactions would you predict to have a largest orientation factor? | H(g) + F(g) --> HF(g) |
| Which rate law is termolecular? | rate=k[A][B]^2 |
| Which rate law is bimolecular? | rate=k[A][B] |
| k | A |
| n, in Rate= k[A]^n | reaction order |
| t1/2 | half-life |
| Ea | activation energy |
| A | frequency factor |
| Define half-life | a reaction is the time required for the concentration of a reaction to fall to one-half of its initial value |
| Define activation energy | shows the energy of the molecule as the reaction proceeds |
| Define frequency factor | represents the number of approaches to the activation barrier per unit |