Structured Responses: Reaction Conditions

Question 1

Pressure Increase

Answer 1

If the pressure of the reaction vessel is increased, the rate of reaction is also increased. More particles are present within a defined volume as the increased pressure decreases the volume. This increases the probability of a productive collision per unit time by concentrating reactant particles.

Question 2

Pressure Decrease

Answer 2

If the pressure of the reaction vessel is decreased, the rate of reaction is also decreased. Less particles are present within a defined volume as the decreased pressure increases the volume. This decreases the probability of a productive collision per unit time by reducing the concentration of reactant particles.

Question 3

Temperature Increase

Answer 3

If the temperature of the reaction vessel is increased, more particles will have energy equal to or greater than that of the activation energy barrier. This results in a greater frequency of productive collisions per unit time, thus increasing the rate of reaction.

Question 4

Temperature Decrease

Answer 4

If the temperature of the reaction vessel is decreased, less particles will have energy equal to or greater than that of the activation energy barrier. This results in a lower frequency of productive collisions per unit time, thus decreasing the rate of reaction.

Question 5

Surface Area Increase

Answer 5

If the surface area of the reactant particles is increased, the rate of reaction is also increased. There is a greater amount of reactant available which results in a greater frequency of productive collisions per unit time.

Question 6

Surface Area Decrease

Answer 6

If the surface area of the reactant particles is decreased, the rate of reaction is also decreased. There is a lesser amount of reactant available which results in a lower frequency of productive collisions per unit time.

Question 7

Catalysts (there is no vice-versa)

Answer 7

Catalysts increase the rate of reaction by providing an alternate pathway of reactions that have lower activation energy. This results in more reactant particles having energy equal to or greater than that of the activation energy barrier resulting in an increased reaction rate.