Unit 8 Test

Which statement explains why the speed of

some chemical reactions is increased when the

surface area of the reactant is increased?

• This change alters the electrical

  conductivity of the reactant particles.

• This change exposes more reactant

  particles to a possible collision.

• This change increases the density of the

  reactant particles.

• This change increases the concentration of

  the reactant.

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

• orientation and potential energy 
• kinetic energy and temperature 
• kinetic energy and orientation 
• potential energy and kinetic energy 

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

• sufficient rate and sufficient energy
• sufficient surface area and correct orientation
• sufficient catalyst and sufficient energy
• sufficent energy and correct orientation

More collisions correspond to a: 

• Faster reaction rate  
• Slower reaction rate
• Constant reaction rate 
• None of the above

Reaction rate means...

• amount of product formed
• speed of reaction
• concentration of reacting particles
• combining reactants with products

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

• Place the reactants in hot water
• Place the products in ice bath
• Place the reactants in a ice bath
• Keep stirring the reactants with a stirring rod

Which of the following increase the reaction rate?

• less surface area
• lower temperature
• an inhibitor
• increased concentration

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

• it increases both the frequency and 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

What is the purpose of a catalyst?

• Helps to slow down a reaction

• Raises the activation energy

• Lowers the activation energy

• Is consumed by the reaction

What factors effect rate of reaction?

• Temperature, Concentration, Pressure and Energy

• Surface Area, Concentration, Energy and Pressure

• Temperature, Pressure, Concentration and Surface area

• Pressure, Surface area, Density and Energy