Kinetics Quiz 2

Under the collision theory, the particles must collide with  ____ and ____ for a reaction to occur.

• sufficient rate and sufficient energy
• sufficient surface area and correct orientation
• sufficient catalyst and sufficient energy
• sufficent energy and correct orientation

Why does a higher temperature increase the rate of a reaction?

• it increases both the frequency and energy of particle collisions
• it only increases the frequency of particle collisions
• it only increases the energy of particle collisions
• it reduces the activation energy of the reaction

Tags

NGSS.HS-PS1-5

The diagram shows the energy profile for a catalyzed and uncatalyzed reaction. Which selection below gives the enthalpy change, ΔH, and the activation energy, E_a, for the catalyzed reaction?

• ΔH is z, E_a is x + z

• ΔH is z, E_a is z + y

• ΔH is -z, E_a is x

• ΔH is z + x, E_a is x

Which quantity can be changed by the use of a catalyst?

• I and II only

• I and III only

• II and III only

• I, II and III

Which change increases the rate of a chemical reaction?

• Increasing the size of solid reactant particles

• Decreasing the concentration of aqueous reactants

• Increasing the surface area of a solid reactant

• Decreasing the pressure of gaseous reactants

In the image shown, the first reaction does not result in a reaction, but the second does because:

• The orientation of the collision in the first example is not correct.

• Not all collisions result in a reaction

• The second reaction is more thermodynamically favorable

• The energy is below Ea in the first example, but above Ea in the second example.

The activated complex will be present at what point in this profile?

• W

• X

• Y

• Z

The reaction 2NO + O₂ → 2NO₂ obeys the rate law:

Rate = k[NO]²[O₂].

Evaluate each of the mechanisms below. Determine which mechanism is most likely.

• NO + NO → N₂O₂ (slow)

  N₂O₂ + O₂ ↔2NO₂ (fast, equilibrium)

• 2NO ↔ N₂O₂ (fast, equilibrium)

  N₂O₂ → NO₂ + O (slow)

  NO + O → NO₂ (fast)

• NO + O₂ ↔ NO₃ (fast, equilibrium)

  NO₃ + NO → 2NO₂ (slow)

• 2NO + O₂ → 2NO₂ (one step)

What is the activation energy, E_a, for this reaction?

• 100 kJ

• 250 kJ

• 50 kJ

• 200 kJ

Is this an endothermic or exothermic reaction?

• endothermic

• exothermic

Tags

NGSS.HS-PS1-4