Chemical Reactions Quiz

What is meant by the rate of a chemical reaction?

• The total mass of reactants used

• The total volume of products formed

• The speed at which reactants are converted to products

• The time taken to mix the reactants

Which factor does NOT affect the rate of a chemical reaction?

• Temperature

• Color of the reactants

• Concentration

• Surface area

According to collision theory, reactions occur when particles:

• Are in a solid state

• Have low energy

• Collide with enough energy and correct orientation

• Are at room temperature

Increasing the temperature increases the rate of reaction because:

• It increases the volume of the reaction vessel

• It decreases activation energy

• Particles move slower

• Particles gain more kinetic energy and collide more frequently

What is the role of a catalyst in a chemical reaction?

• Increases product concentration

• Decreases the energy of reactants

• Increases activation energy

• Provides an alternative pathway with lower activation energy

Which graph best represents the rate of a reaction over time?

• A straight horizontal line

• A curve that levels off

• A line sloping upward continuously

• A zigzag pattern

How does increasing the concentration of a reactant affect the rate of reaction?

• It decreases the rate

• No effect

• Increases the frequency of collisions

• Increases the mass of the product

Which change will increase the surface area of a solid reactant?

• Compressing it into a block

• Freezing it

• Breaking it into smaller pieces

• Melting it

Which of these would speed up the decomposition of hydrogen peroxide?

• Decreasing the temperature

• Adding manganese dioxide catalyst

• Diluting the solution

• Using a smaller container

What is activation energy?

• The energy released in a reaction

• The total energy in the system

• The energy needed to start a reaction

• The energy required to stop a reaction