Collision Theory and Reaction Rate

The following graph shows two different reaction pathways for the same overall reaction at the same temperature. Which pathway is slower and why?

• Red, because the activation energy is larger

• Blue, because the activation energy is lower

• both reaction progress at the same rate

Tags

NGSS.HS-PS1-4

What criteria must be met for reactant collisions to result in a successful product?

• The reactants must collide with each other

• The reactants must collide with enough energy and be in the right positions

• The reactants must have enough energy to form the activated complex

Tags

NGSS.HS-PS1-5

Which of the following is/are the fundamental idea(s) of collision theory?

• Molecules react by colliding together

• The effective collisions must occur with certain minimum amounts of energy 

• In a large sample, the greater the number of effective collisions, and the faster the rate of reaction

• All of the above

Tags

NGSS.HS-PS1-5

Which among the following is NOT TRUE about the collision theory and the rate of reaction?

• higher temperature ---> faster particle movements ---> more collision

• higher concentration ---> more spaces between particles ---> more collision

• higher surface area ---> more particle interactions ---> more collision

Tags

NGSS.HS-PS1-5

What is meant by collision frequency in the context of collision theory?

• The number of collisions that result in a reaction

• The number of collisions per unit time

• The speed at which particles move

• The energy required for a collision to be effective

Tags

NGSS.HS-PS1-5

How does increasing the temperature affect the rate of a chemical reaction?

• It decreases the collision frequency

• It increases the collision frequency

• It has no effect on the collision frequency

• It decreases the energy of collisions

Tags

NGSS.HS-PS1-5

How does increasing the surface area of a solid reactant affect the reaction rate?

• It decreases the reaction rate

• It increases the reaction rate

• It has no effect on the reaction rate

• It decreases the energy of collisions

What role does concentration play in the rate of reaction according to collision theory?

• Higher concentration decreases the number of effective collisions

• Higher concentration increases the number of effective collisions

• Concentration has no effect on the number of effective collisions

• Higher concentration decreases the collision frequency

Tags

NGSS.HS-PS1-5

Crushing a solid catalyst into finer particles before adding it to a reaction mixture will:

• Decrease the reaction rate.

• Have no effect on the reaction rate.

• Increase the reaction rate.

• Stop the reaction.

Answer explanation

Increasing the surface area of a solid reactant will increase the reaction rate by providing more area for collisions between reactant particles.

What is the significance of the activation energy in a chemical reaction?

• It is the energy released during the reaction

• It is the minimum energy required for reactants to transform into products

• It determines the color of the reaction mixture

• It is the energy required to break bonds in the products