7.1 Rates of Reaction

• How does a higher concentration of reactants affect the rate of reaction?

  Increases the rate
• What is the definition of the rate of reaction?

  Speed of chemical reaction
• The rate of reaction is usually expressed as the change in concentration of reactants or products per unit time
• Increasing the temperature always decreases the rate of reaction.

  False
• The minimum energy required for a reaction to occur upon collision is called activation energy.
• Order the following variables based on their relationship to the rate of reaction:

  1️⃣ High Rate of Reaction

  2️⃣ Reactants Used/Formed Quickly

  3️⃣ Shorter Time
• How does increasing the concentration of reactants affect the rate of reaction?

  Increases the rate
• Higher temperatures increase the kinetic energy of reactant molecules, leading to more frequent and successful collisions.

  True
• Activation energy is the minimum energy required for a reaction to start.


  True
• In the reaction between hydrogen and iodine, what must molecules collide with sufficient kinetic energy to break?

  H-H and I-I bonds
• Arrange the effects of temperature on reaction rate from lowest to highest:

  1️⃣ Lower kinetic energy

  2️⃣ Less frequent collisions

  3️⃣ Slower reaction rate

  4️⃣ Higher kinetic energy

  5️⃣ More frequent collisions

  6️⃣ Faster reaction rate
• Higher concentrations of reactants lead to more frequent collisions and a faster reaction rate.


  True
• In the reaction forming water from hydrogen and oxygen, what happens to the reaction rate if the concentrations of both gases are increased?

  Becomes faster
• Match the example with the effect of surface area on reaction rate:

  Burning coal dust ↔️ Burns faster than a lump of coal

  Granulated sugar ↔️ Dissolves quicker than a sugar cube
• What happens to the activation energy and reaction rate when a catalyst is present?

  Activation energy is lower, rate is faster
• What is the definition of the rate of reaction?

  Speed at which reaction occurs
• The rate of reaction is usually expressed as the change in concentration of reactants or products per unit time
• How does temperature affect the rate of a chemical reaction?

  Increases the rate
• Higher concentrations of reactants increase the frequency of collisions
• How do catalysts affect the activation energy of a reaction?

  Lower it
• Conditions for a successful collision in collision theory:

  1️⃣ Kinetic energy is sufficient

  2️⃣ Orientation is correct
• What is activation energy?

  Minimum energy for reaction
• In the reaction between hydrogen and iodine, iodine molecules must be aligned correctly
• What happens to the rate of reaction at lower temperatures?

  Slower
• A larger surface area of solid reactants increases the frequency of collisions
• Why does coal dust burn faster than a lump of coal?

  Greater surface area
• Catalysts provide an alternative reaction pathway with lower activation energy.


  True
• What is the effect of a catalyst on the rate of reaction?

  Speeds it up
• Gas volume measurement is used for reactions producing gas
• How do catalysts improve industrial processes?

  Lower activation energy
• For reactions involving solid reactants, increasing the surface area increases the rate
• Catalysts are consumed during a reaction to lower the activation energy.

  False
• What two conditions must be met for a successful collision according to collision theory?

  Sufficient energy and correct orientation
• Higher temperatures increase the kinetic energy of molecules, leading to more frequent collisions.


  True
• How does a higher concentration of reactants affect the frequency of collisions?

  Increases the frequency
• At lower concentrations, the frequency of collisions is less frequent, resulting in a slower reaction rate.
• Temperature increases the rate of reaction by providing molecules with more kinetic energy for successful collisions.


  True
• For reactions involving solid reactants, a larger surface area increases the rate by exposing more reactant particles for collision
• Match the factor with its effect on reaction rate:

  Temperature ↔️ Increases kinetic energy

  Catalysts ↔️ Lower activation energy

  Concentration ↔️ Increases collision frequency
• What two conditions are necessary for a successful collision in collision theory?

  Sufficient kinetic energy and correct orientation