Question

Use the PhET Reactions & Rates interactive simulation to simulate a system. On the "Single collision" tab of the simulation applet, enable the "Energy view" by clicking the "+" icon. Select the first A+BC⟶AB+C reaction (A is yellow, B is purple, and C is navy blue). Using the "angled shot" option, try launching the A atom with varying angles, but with more Total energy than the transition state. What happens when the A atom hits the BC molecule from different directions? Why?

a) The reaction rate increases; more collisions occur.
b) The reaction becomes less exothermic; less energy is released.
c) The reaction becomes more exothermic; more energy is released.
d) The reaction outcome remains unchanged; angle has no effect.

Answer 1

In the PhET Reactions & Rates simulation, when more total energy than the transition state energy is provided, changing the collision angle does not affect the outcome of the A + BC → AB + C reaction.

Step-by-step explanation:

When the A atom in the PhET Reactions & Rates interactive simulation hits the BC molecule from different angles using the "angled shot" option, the reaction outcome remains unchanged; this is because the angle of collision does not affect the reaction when there is more total energy than the transition state energy barrier. The influence of collision angle on reaction rate is more about whether the reactants have the necessary orientation for a successful collision that can lead to a reaction, rather than the amount of energy released in the reaction.

When it comes to reaction rates, bypassing the orientation factor by supplying enough energy ensures the reactants overcome the activation energy barrier, leading to a successful reaction regardless of the collision angle. Therefore, for a reaction with excess energy, changing the collision angle won't have any significant impact on the reaction outcome.