Ch.14 - Chemical Kinetics
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- Use the following equation and graph to answer questions 1 and 2. Hydrogen iodide decomposes at 410 °C, according the reaction: 2 HI1g2¡H21g2 + I21g2 The graph shows how the concentration of HI changes over time. What is the average rate of loss of HI over the time period 0–40 s (LO 14.1) (a) 7.5 * 10-3 M>s (b) 4.8 * 10-3 M>s (c) 3.0 * 10-2 M>s (d) 3.5 * 10-3 M>s
Problem 1
- The gas phase decomposition of HI has the following rate law: 2 HI1g2¡H21g2 + I21g2 Rate = k3HI42 At 443 °C, k = 30.1 M-1 min-1. If the initial concentration of HI is 0.010 M, what is the concentration after 1.5 hours? (LO 14.8) (a) 6.9 * 10-3 M (b) 1.8 * 10-3 M (c) 3.6 * 10-4 M (d) 8.9 * 10-4 M
Problem 8
- Chlorine monoxide (ClO) decomposes at room temperature according to the reaction 2 ClO1g2¡Cl21g2 + O21g2 The concentration of ClO was monitored over time, and three graphs were made:
Problem 9
What is the rate law for the reaction? (LO 14.9) (a) Rate = k (b) Rate = k3ClO4 (c) Rate = k3ClO42 (d) Rate = k3ClO43 M14_MCMU6230_
- A key reaction in the upper atmosphere is O31g2 + O1g2 ¡ 2 O21g2 For this process, the energy of activation for the forward reaction, Ea1fwd2, is 19 kJ/mol, and the enthalpy change for the reaction, ΔHrxn, is -392 kJ>mol. What is the energy of activation for the reverse reaction, Ea1reverse2? (LO 14.10) (a) 411 kJ/mol (b) 392 kJ/mol (c) 373 kJ/mol (d) 196 kJ/mol
Problem 11
- To answer questions 13–15, refer to the mechanism: H2O21aq2 + I-1aq2¡OH-1aq2 + HOI1aq2 Slower, rate-determining HOI1aq2 + I-1aq2¡OH-1aq2 + I21aq2 Faster 2 OH-1aq2 + 2 H3O+1aq2¡4 H2O1l2 Faster Identify the catalyst and intermediate(s) in the mechanism. (LO 14.12, 14.16) (a) Catalyst = I-, intermediates = OH-, HOI (b) Catalyst = H3O+, intermediate = HOI (c) No catalyst, intermediate = I2 (d) No catalyst, intermediates = OH-, HOI
Problem 13
- What is the total amount of heat absorbed (in kilojoules) after a reaction time of 10.0 min for the first-order decomposition of gaseous N2O5 to NO2 and O2 at 55 °C, given that the rate constant is 1.7 * 10^-3 s^-1?
Problem 14
- (b) Write the balanced reaction that corresponds to the data in the graph.
Problem 39
![Graph showing concentration changes of reactants [X], [Y], and product [Z] over time in a chemical reaction.](https://lightcat-files.s3.amazonaws.com/problem_images/43642d15778f4d2c-1672153351677.jpg)
Problem 40a
The following reaction is first order in A (red spheres) and first order in B (blue spheres): A + B → Products Rate = k[A][B]
(a) What are the relative rates of this reaction in vessels (1)–(4)? Each vessel has the same volume.