JustAnswer
Question 1
1. Which of the following statements is always true?Answer
|Exothermic reactions have lower activation energies than endothermic reactions. |
|The rate for a reaction depends on the concentrations of all the reactants. |
|The rate of a catalyzed reaction is independent of the concentration of the catalyst. |
|The rate constant is independent of the concentrations of the reacting species. |
|The rate law can be determined from the stoichiometric equation. |
5 points
Question 2
1. For the formation of 1 mol of nitrosyl chloride at a given temperature, ΔH = -40 kJ.
NO(g) + ½Cl2(g) → NOCl(g)
The activation energy for this reaction is 84 kJ/mol. What is the activation energy for the reverse reaction?Answer
|-40 kJ/mol |
|44 kJ/mol |
|84 kJ/mol |
|124 kJ/mol |
|-124 kJ/mol |
5 points
Question 3
1. The rate constant for a reaction at 40.0°C is exactly 2 times that at 20.0°C. Calculate the Arrhenius energy of activation for the reaction.Answer
|2.00 kJ/mol |
|5.8 kJ/mol |
|26.4 kJ/mol |
|3.18 kJ/mol |
|none of these |
5 points
Question 4
1. The following mechanism has been suggested for the reaction between nitrogen monoxide and oxygen:
NO(g) + NO(g) ↔ N2O2(g) (fast)
N2O2(g) + O2(g) → 2NO2(g) (slow)
According to this mechanism, the experimental rate law isAnswer
|second-order in NO and zero-order in O2. |
|second-order in NO and first-order in O2. |
|first-order in NO and first-order in O2. |
|first-order in NO and second-order in O2. |
|first-order in NO and zero-order in O2. |
5 points
Question 5
1. Which of the following corresponds to the correct integrated expression for a first-order reaction?Answer
|[pic] |
|[pic] |
|[pic] |
| |
|[pic] |
|View Full Image |
|[pic] |
| |
|[pic] |
|[pic] |
|[pic] |
| |
|[pic] |
|View Full Image |
|[pic] |
| |
|[pic] |
|[pic] |
|[pic] |
| |
|[pic] |
|View Full Image |
|[pic] |
| |
|[pic] |
|[pic] |
|[pic] |
| |
|[pic] |
|View Full Image |
|[pic] |
| |
|[pic] |
|[pic] |
|[pic] |
| |
|[pic] |
|View Full Image |
|[pic] |
| |
5 points
Question 6
1. For a certain second-order decomposition reaction, the rate is 0.48 mol/(L · s) when the concentration of the reactant is 0.33 mol/L. What is the rate constant for this reaction?Answer
|1.45 L/(mol · s) |
|0.48 L/(mol · s) |
|0.23 L/(mol · s) |
|0.69 L/(mol · s) |
|4.4 L/(mol · s) |
5 points
Question 7
1. The oxidation of ammonia produces nitrogen and water via the following reaction:
4NH3(g) + 3O2(g) → 2N2(g) + 6H2O(l)
Suppose the rate of formation of H2O(l) is 3.0 mol/(L · s). Which of the following statements is true?Answer
|The rate of formation of N2 is 2.0 mol/(L · s). |
|The rate of consumption of NH3 is 2.0 mol/(L · s). |
|The rate of consumption of O2 is 2.0 mol/(L · s). |
|The rate of consumption of NH3 is 0.50 mol/(L · s). |
|The rate of formation of N2 is 1.3 mol/(L · s). |
5 points
Question 8
1. Below is a proposed mechanism for the decomposition of H2O2.
H2O2 + I- → H2O + IO- slow
H2O2 + IO- → H2O + O2 + I- fast
Which of the following statements is incorrect?Answer
|The reaction is first-order with respect to [I-]. |
|The reaction is first-order with respect to [H2O2]. |
|I- is a catalyst. |
|The net reaction is 2H2O2 → 2H2O + O2. |
|IO- is a catalyst. |
5 points
Question 9
1. The rate constant for a first-order reaction is 1.6 × 10-2 s-1 at 738 K and 3.5 × 10-2 s-1 at 918 K. What is the activation energy?Answer
|11 kJ/mol |
|24 kJ/mol |
|2900 kJ/mol |
|24 kJ/mol |
|11 kJ/mol |
5 points
Question 10
1. The nuclide 96Nb decays by a first-order process with a rate constant of 2.96 × 10-2 h-1. How long will it take for 69.0% of the initial amount of 96Nb to be consumed?Answer
|39.6 h |
|23.3 h |
|33.8 h |
|12.5 h |
|10.5 h |
5 points
Question 11
1. For a given reaction, the rate constant, k, was determined at different temperatures. To obtain the activation energy, one should plotAnswer
|k vs. T. |
|log k vs. T. |
|ln k vs. T. |
|k vs. 1/T. |
|ln k vs. 1/T. |
5 points
Question 12
1. In aqueous solution, iodine reacts with acetone as represented by the following equation:
I2(aq) + CH3COCH3(aq) → CH3COCH2I(aq) + H+(aq) + I-(aq)
The experimental rate law is Rate = k[H+][CH3COCH3]. According to the information above, an increase in the hydrogen ion concentration has what effect on the reaction?Answer
|It increases the value of the equilibrium constant. |
|It decreases the value of the equilibrium constant. |
|It increases the rate of the reaction. |
|It decreases the rate of the reaction. |
|It does not affect the rate of the reaction. |
5 points
Question 13
1. A reaction that is second-order in one reactant has a rate constant of 2.0 × 10-2 L/(mol · s). If the initial concentration of the reactant is 0.240 mol/L, how long will it take for the concentration to become 0.120 mol/L?Answer
|35 s |
|104 s |
|210 s |
|2100 s |
|350 s |
5 points
Question 14
1. A mechanism that explains the rate law, Rate = k[(CH3)3CO2C(CH3)3], for the gas-phase thermal decomposition of di-tert-butyl peroxide is given below.
|[|[pic] |[|
|p| |p|
|i| |i|
|c| |c|
|]| |]|
|[|View Full Image |[|
|p| |p|
|i| |i|
|c| |c|
|]| |]|
2.
For this reaction, the rate-determining step(s) must beAnswer
|step 1. |
|step 2. |
|step 3. |
|2 times step 2. |
|step 1 + step 2 + step 3. |
5 points
Question 15
1. Consider the reaction
aA + bB
|[|[pic] |[|
|p| |p|
|i| |i|
|c| |c|
|]| |]|
|[|View Full Image |[|
|p| |p|
|i| |i|
|c| |c|
|]| |]|
2. dD + eE C = catalyst
The rate law is
Rate = k[A]qr[C]s
Which of the following statements is incorrect?Answer
|The exponents q, r, and s are often integers. |
|The exponents q and r are always equal to the coefficients a and b, respectively. |
|The exponent s must be determined experimentally. |
|The symbol k represents the rate constant. |
|The overall reaction order is q + r + s. |
5 points
Question 16
1. For the hypothetical first-order reaction A → products, k = 0.0472 s-1. If the initial concentration of A is 0.671 M, how long would it take for A to be 81.8% consumed?Answer
|36.1 s |
|21.2 s |
|14.7 s |
|4.26 s |
|31.6 s |
5 points
Question 17
1. A second-order reaction starts with an initial concentration of 0.100 mol/L of the reactant. If the rate constant is 2.2 × 10-2 L/(mol · s), what is the time required to decrease the initial concentration to 0.050 mol/L?Answer
|450 s |
|31.5 s |
|2.27 s |
|1400 s |
|680 s |
5 points
Question 18
1. For the elementary reaction A + B → C + D, what is the predicted rate law?Answer
|Rate = k[A] |
|Rate = k[A]2 |
|Rate = k2 |
|Rate = k |
|[pic] |
|[pic] |
|[pic] |
| |
|[pic] |
|View Full Image |
|[pic] |
| |
|Rate = k[A]/[C] |
5 points
Question 19
1. The complete mechanism for a reaction is considered to occur in two steps, one of which is slow and the other fast:
A + 2B → C + D slow
A + C → E + F fast
What is the rate law predicted by this mechanism?Answer
|Rate = k[A]2 |
|Rate = k[A][C] |
|Rate = k[A]2[C] |
|Rate = k[A][C] |
|Rate = k[A]2 |
5 points
Question 20
1. The reaction between selenous acid and the iodide ion in acid solution is
H2SeO3(aq) + 6I-(aq) + 4H+(aq) → Se(s) + 2I3-(aq) + 3H2O(l)
The data in the following table were measured at 0°C.
|Experiment |[H2SeO3]0 (M) |[H+]0 (M) |[I-]0 (M) |Initial Rate [mol/(L · s)] |
|1 |1.00 × 10-4 |2.00 × 10-2 |3.00 × 10-2 |5.30 × 10-7 |
|2 |2.00 × 10-4 |2.00 × 10-2 |3.00 × 10-2 |1.06 × 10-6 |
|3 |3.00 × 10-4 |4.00 × 10-2 |3.00 × 10-2 |6.36 × 10-6 |
|4 |3.00 × 10-4 |8.00 × 10-2 |3.00 × 10-2 |2.54 × 10-5 |
|5 |3.00 × 10-4 |8.00 × 10-2 |6.00 × 10-2 |2.04 × 10-4 |
|6 |2.00 × 10-4 |2.00 × 10-2 |6.00 × 10-2 |8.48 × 10-6 |
2. Tripling the initial concentration of I- while holding the initial concentrations of H2SeO3 and H+ constant increases the initial rate of the reaction by a factor ofAnswer
|3. |
|6. |
|8. |
|9. |
|27. |
5 points
Question 21
1. For the first-order reaction
½N2O4(g) → NO2(g); ΔH = 28.6 kJ
the activation energy is 53.7 kJ/mol. What is the activation energy for the reverse reaction?Answer
|25.1 kJ/mol |
|15.2 kJ/mol |
|53.7 kJ/mol |
|82.3 kJ/mol |
|-53.7 kJ/mol |
................
................
In order to avoid copyright disputes, this page is only a partial summary.
To fulfill the demand for quickly locating and searching documents.
It is intelligent file search solution for home and business.