Chapter 14 quiz PDF

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Chapter 14 quiz...

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1. Of the following, all are valid units for a reaction rate except ________. A) mol/L B) M/s C) mol/hr D) g/s E) mol/L-hr

2. Which one of the following is not a valid expression for the rate of the reaction below? 4NH3 + 7O2 → 4NO2 + 6H2O 1 ∆[O2 ] ∆t

A) − 7 B)

1 ∆[NO2 ] 4 ∆t

C)

1 ∆[H2 O] 6 ∆t 1 ∆[NH2 ]

D) − 4

∆t

E) All of the above are valid expressions of the reaction rate.

3. As the temperature of a reaction is increased, the rate of the reaction increases because the _______ A) Reactant molecules collide less frequently. B) Reactant molecules collide more frequently and with greater energy per collision. C) Activation energy is lower. D) Reactant molecules collide less frequently and with greater energy per collision. E) Reactant molecules collide more frequently and with less energy per collision.

4. The rate of a reaction depends on ______. A) Collision frequency B) Collision energy C) Collision orientation D) All of the above E) None of the above

5. For A + B → P, the data below yields a rate constant of ______. Experiment Number 1 2 3

[A [A]] M 0.273 0.273 0.819

[B] M Initial Rate (M/s) 0.763 2.83 1.526 2.83 0.763 25.47

6. For A → B, is second order in [A] and the rate constant is 0.025 M-1s-1: The concentration of A was 0.65 M at 33 s. The initial concentration of A was ______ M.

Answers 1.

2.

3. One of the factors that affect reaction rate is temperature. Reaction rate generally increases with increasing temperature because molecules move faster, increasing the collisions frequency and energy during the collisions. Therefore, by increasing the temperature of the reaction the rate of the reaction is increased since the reactant molecules collide more frequently and with greater energy per collision. Answer: Option C.

4. The rate of a reaction is dependent on the reactants collisions. More collisions = more reactions. When the reactants collision in a higher frequency and energy more product will form, and the greater the reaction rate will be. In addition, molecules can often collide without forming products, aligning molecules properly can lead to chemical reactions. To break and form bonds that will result in forming a product, atom need to be in proper position. Therefore, the reaction rate depend on the collision frequency, energy, and orientation. Answer: Option D.

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