7.1 Rates of Reaction

• The rate of reaction is the speed at which reactants are converted into products
• Higher concentration increases the frequency of collisions between reactant molecules.


  True
• What effect does higher pressure have on the rate of reaction for gases?

  Increases it
• What type of energy must particles have to overcome the activation energy barrier?

  Kinetic energy
• Ineffective collisions can occur if particles have sufficient kinetic energy but incorrect orientation.

  True
• The instantaneous rate of reaction is calculated using the slope of the tangent on a reaction curve.

  True
• Match the key terms with their definitions:

  Reactants ↔️ Substances consumed in the reaction

  Products ↔️ Substances formed in the reaction

  Concentration ↔️ Amount of substance in a volume

  Time ↔️ Duration of the reaction
• What is the definition of the rate of reaction?

  Speed of chemical reaction
• If 50g of a reactant is used up in 10 minutes, the average rate of reaction is 5 g/min
• Increased surface area provides more contact points for reactions to occur
• Collision theory states that for a reaction to occur, particles must have the correct orientation
• What is the definition of the average rate of reaction?

  Rate over a time period
• The instantaneous rate of reaction is determined by the slope of the tangent
• How is the rate of reaction calculated?

  Change in amount / Time
• How does increasing the concentration of reactants affect the rate of reaction?

  Increases the rate
• What role do catalysts play in chemical reactions?

  Speed up the reaction
• How does higher pressure affect the reaction rate of gases?

  It increases
• Higher concentration of reactants increases the reaction rate.


  True
• Powdered substances react faster than large blocks due to increased surface area.
• What are the two requirements stated by collision theory for a reaction to occur?

  Correct orientation and sufficient kinetic energy
• What is activation energy defined as?

  Minimum energy for reaction
• Match the type of reaction rate with its definition:

  Average Rate ↔️ The average speed of the reaction over a period

  Instantaneous Rate ↔️ The rate at a specific moment
• The instantaneous rate of reaction is defined as the rate at a specific moment
• The rate of reaction is calculated by dividing the change in amount of reactant or product by the time taken.


  True
• Why does higher pressure increase the reaction rate for gases?

  Increases collision frequency
• What is the formula for calculating the average rate of reaction?

  (Change in reactant) / Time
• If 50g of reactant is used up in 10 minutes, what is the average rate of reaction?

  5g/min
• Powdered substances react faster than large blocks due to increased surface area.

  True
• Catalysts are consumed during a reaction.

  False
• The kinetic energy of colliding particles must exceed the activation energy.
• In the reaction H₂ + O₂ → H₂O, what conditions are necessary for the formation of water?

  Correct alignment and sufficient energy
• To measure reaction rates, you can use the average rate or the instantaneous rate.
• How do catalysts increase the rate of a chemical reaction?

  Lower activation energy
• The average rate of reaction is calculated over a specific time period
• Heating a mixture increases the kinetic energy of reactant molecules, leading to more effective collisions and a higher reaction rate.


  True
• What happens to the reaction rate when temperature increases?

  It increases
• Catalysts lower the activation energy required for a reaction.
• What is the effect of increasing the concentration of reactants on the reaction rate?

  More frequent collisions
• What is the role of catalysts in a chemical reaction?

  Lower activation energy
• Molecules must collide with the correct orientation to form new bonds.

  True