Big Idea 8 Exam Review

What two factors determine whether a collision between reacting particles will be effective?

• Orientation and activation energy

• Orientation and potential energy

• Potential energy and kinetic energy

• Temperature and concentration

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

• sufficient rate and sufficient energy

• sufficient catalyst and sufficient energy

• sufficient surface area and correct orientation

• sufficient energy and correct orientation

More collisions correspond to a: 

• Faster reaction rate

• Constant reaction rate

• Slower reaction rate

• None of these

Increasing surface area increases the reaction rate because

• 
  It makes particles move faster

• It increases the exposed particles available to react

• It increases the likelihood of collisions with the correct geometry

• It increases the number of particles available to react

To slow down a chemical reaction you will do one of the following:

• Place the reactants in hot water

• Place the reactants in a ice bath

• Keep stirring the reactants with a stirring rod

• Increase the concentration of the reactants

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

• it increases both the frequency and kinetic 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

How does a catalyst work in speeding up a reaction?

• By providing an alternate pathway with lower activation energy

• By lowering the kinetic energy

• By increasing the enthalpy

• By exposing more particles for collisions

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

• Red, because the activation energy is larger

• Blue, because the activation energy is smaller

• Both reaction progress at the same rate because the start and end with the same PE

Why does a higher concentration increase the rate of reaction?

• it increases the amount of reactants molecules available

• It exposes more particles for collisions

• It lowers the activation energy

• It increases the kinetic energy

Grinding a Alka-Seltzer tablet into powder increases the rate of reaction due to increased

• concentration

• surface area

• temperature

• pressure