15. Chemical Kinetics

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A chemist tries to burn sulfur in air and notices that it burns very slowly. Chemist then burns sulfur in pure oxygen and observes a brilliant blue flame. Which factor is affecting the reaction rate?

633

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The rate law for a particular mechanism is expressed as rate = [A]²[B]. If [A] is halved and [B] is doubled, how would the overall rate be affected?

144

Identify the intermediate in the mechanism below:

Step 1: NO₂ → NO + O
Step 2: O + NO₂ → O₂ + NO

102

Calculate the activation energy for the reaction that has a rate constant of 0.124 s^–1 at 125.0 °C and a rate constant of 0.345 at 200.0 °C.

160

Which of the following statements is false about the effect of temperature on the reaction rate?

188

(b) Name three factors that can affect the rate of a chemical reaction.

417

(b) As the temperature increases, does the reaction rate increase or decrease?

466

Indicate whether each statement is true or false. (b) Exothermic reactions are faster than endothermic reactions.

511

Many metallic catalysts, particularly the precious-metal ones, are often deposited as very thin films on a substance of high surface area per unit mass, such as alumina 1Al2O32 or silica 1SiO22. (b) How does the surface area affect the rate of reaction?

210

Consider the reaction H21g2 + I21g2S 2 HI1g2. The reaction of a fixed amount of H2 and I2 is studied in a cylinder fitted with a movable piston. Indicate the effect of each of the following changes on the rate of the reaction. (c) The addition of a catalyst

139

158

Values of Ea = 6.3 kJ>mol and A = 6.0 * 108>1M # s2 have been measured for the bimolecular reaction: NO1g2 + F21g2S NOF1g2 + F1g2 (d) Why does the reaction have such a low activation energy?

148

How will increasing the surface area of one or more reactants affect the reaction rate of a system?

What two factors speed up rates of chemical reaction and weathering in rocks and soils?

Which of the following could increase the rate of chemical weathering of a rock?

Which of the following factors directly impacts the rate at which a liquid evaporates?

What happens to the reaction rate as the reactants get used up in a reaction?