Reaction Rates Review

What is the effect of a catalyst on the required energy to achieve effective collisions?
A catalyst lowers the required energy (activation energy) for a reaction to take place.
A catalyst does not affect the required energy (activation energy) for a reaction to take place.
A catalyst increases the required energy (activation energy) for a reaction to take place.
How does decreasing temperature affect the rate of reaction.
Decreasing temperature decreases the rate of reaction.
Decreasing temperature increases the rate of reaction.
Decreasing temperature does nothing to the rate of reaction.
When a titration is complete, what two things are equal?
the moles of hydrogen ions and the moles of hydroxide ions
the volume of acid and the volume of base
the moles of acid and the moles of base
the volume of hydrogen ions and the volume of hydroxide ions
Reaction rate measures the speed at which reactants:
disappear
appear
In order for a collision to be considered effective, the reactant particles must have the correct orientation and the proper amount of:
energy
space
concentration
surface area
Which of the following will NOT speed up a chemical reaction?
decreasing the temperature
increasing the concentration
adding a catalyst
increasing the surface area
The way to increase the rate of a reaction is to increase the number of effective collisions
True
False
A catalyst is considered a reactant in a chemical reaction.
False
True

Based on your knowledge of factors affecting the rate of reaction, why is there a danger of explosions in places such as silos and coal mines where there are large quantities of powdered, combustible materials?

Click to reveal the answer.

Powdered materials have a higher surface area than solid materials. When large quantities of powdered, combustible materials are present, the chances of an effective collision are increased.

 

Due to decomposition reactions with oxygen or carbon dioxide in the air, meat begins to feel slimy and smell spoiled. Explain, using your knowledge of chemical kinetics, why meat spoils less rapidly when left unsliced.

Click to reveal the answer.

Unsliced meat would have a lower surface area. This means that fewer particles are exposed to the oxygen or carbon dioxide in the air, slowing the spoiling.

 

Why would iron filings rust faster than an iron nail?

Click to reveal the answer.

Iron filings have a greater surface area than the nail. This exposes a greater area of contact between the reactants.

 

Why would a mixture of gases react faster when the volume they occupy is decreased?

Click to reveal the answer.

When the volume of the gases is decreased, the particles are forced closer together. This increases the chances of an effective collision.

 

What are the FIVE major factors that affect reaction rate?

Click to reveal answer.

nature of the reactants
concentration of the reactants
temperature
catalyst
surface area

 

What are the TWO characteristics of an effective collision?

Click to reveal answer.

Particles must collide with the correct orientation and the proper amount of energy.

 

 

 


source