Unit 6B In-Class Review

A kinetics experiment is set up to measure the rate of the combustion of organic material (wood) with oxygen gas, O₂, by measuring the volume of carbon dioxide gas, CO₂, generated at 25°C and 1 atm as a function of time.

In general, which does NOT increase the rate of reaction?

Select ALL that apply

• increasing the activation energy

• increasing the temperature of the reaction

• increasing the particle size by using a large block of wood instead of fine particles of sawdust

• increasing the concentration of oxygen reacting with the organic material

Tags

NGSS.HS-PS1-5

For the reaction

2A + B → products

use the experimental data provided to determine the rate law.

• rate = k [A] [B] 

• rate = k [A]

• rate = k [A] [B]⁰ 

• rate = k [A]²

Tags

NGSS.HS-PS1-5

A student collects the following kinetics data for a reaction.  Based on the data, how would you classify the reaction? Why?

• First Order.

  Concentration is halved after 3.00 min and again after another 3.00min. Thus the half-life of the reaction is constant, so the reaction is first order.

• Zero Order.

  Concentration is halved after 3.00 min and again after another 3.00min. Thus the half-life of the reaction is constant, so the reaction is zero order.

• Second Order.

  Concentration is halved after 3.00 min and again after another 3.00min. Thus the half-life of the reaction is constant, so the reaction is second order.

• First Order.

  ln(Concentration) is halved after 3.00 min and again after another 3.00min. Thus the half-life of the reaction is constant, so the reaction is first order.

Consider the equation for the decomposition of N₂O₅(g) and the experimentally determined rate law below.

2N₂O₅(g) ⇌ 4NO₂(g) + O₂(g)

rate=k[N₂O₅]

What are the units for the rate constant, k, with the time measured in minutes?

• M^-1min^-1

• M^-2min^-1

• min^-1

• M^-3min^-1

Tags

NGSS.HS-PS1-5

An increase in temperature will increase the rate of

• an ENDOthermic reaction ONLY

• an EXOthermic reaction ONLY

• BOTH ENDOthermic and EXOthermic reactions

• NEITHER ENDOthermic nor EXOthermic reactions

Tags

NGSS.HS-PS1-5

The rate of formation of NO₂(g) in the reaction

2 N₂O₅(g) → 4 NO₂(g) + O₂(g)

is 5.78 (mol NO₂)/L/s. What is the rate at which N₂O₅ decomposes? 

• 5.78

  (mol N₂O₅)/L/s

• 0.723

  (mol N₂O₅)/L/s

• 2.89

  (mol N₂O₅)/L/s

• 11.6

  (mol N₂O₅)/L/s

Tags

NGSS.HS-PS1-5

NGSS.HS-PS1-7

X + Y → Z

The rate law for the hypothetical reaction shown above is as follows:

Rate = k[X][Y]²

Which of the following changes to the system is true? Select ALL that apply.

• An increase in the temperature will increase the rate

• Doubling the concentration of X will increase the rate more than doubling the concentration of Y

• Doubling the concentration of X will increase the rate less than doubling the concentration of Y

• Doubling the concentration of X will increase the rate the same as doubling the concentration of Y

Tags

NGSS.HS-PS1-5

Which of the following values correspond to the values of the reaction orders x and y for NO and H₂?

• x=2, y=1

• x=2, y=2

• x=1, y=1

• x=1, y=2

Tags

NGSS.HS-PS1-5

Which of the following values correspond to the overall reaction order?

• 3

• 0

• 1

• 2

Tags

NGSS.HS-PS1-5

In the reaction,

NO + O₃ → NO₂ + O₂

the N atom in the NO molecule must strike a terminal O atom in the O₃ molecule. Which of the diagrams below would most likely result in the formation of the products?

• 
• 
• 
• 

Tags

NGSS.HS-PS1-5

NGSS.HS-PS3-4