5.1 Reaction Rate

• Factors affecting reaction rate include temperature, concentration of reactants, and the presence of catalysts.


  True
• In the reaction rate expression, negative signs indicate reactant consumption.


  True
• Higher temperatures increase the kinetic energy of molecules, leading to more effective collisions and a faster reaction rate.

  True
• How do higher temperatures affect the kinetic energy of molecules in a reaction?

  Increase kinetic energy
• Match the factor affecting reaction rate with its effect:

  Concentration of Reactants ↔️ Higher concentrations increase collisions

  Temperature ↔️ Higher temperatures increase kinetic energy

  Catalysts ↔️ Lower activation energy
• Manganese dioxide (MnO₂) is used as a catalyst in the decomposition of hydrogen peroxide.


  True
• What does the integrated rate law method analyze over time?

  Change in concentration
• Why are negative signs used for reactants in the reaction rate expression?

  Concentration decreases
• The units of reaction rate are M/s or mol L⁻¹ s⁻¹
• Match the stoichiometric coefficient with the correct substance in the reaction aA + bB → cC + dD

  a ↔️ Reactant A

  b ↔️ Reactant B

  c ↔️ Product C

  d ↔️ Product D
• Match the factor affecting reaction rate with its effect.

  Concentration of Reactants ↔️ Increases reaction rate by increasing collision frequency

  Temperature ↔️ Increases reaction rate by increasing kinetic energy

  Catalysts ↔️ Speeds up reaction by lowering activation energy
• Catalysts speed up reactions by lowering the activation energy
• Higher reactant concentrations increase the likelihood of collisions, raising the reaction rate.


  True
• Catalysts lower the activation energy, speeding up the reaction.
• What is the primary role of catalysts in a reaction?

  Speed up reaction
• The initial rate method measures the reaction rate at the very start of the reaction.
• In the mathematical expression for reaction rate, `a`, `b`, `c`, and `d` represent the stoichiometric coefficients.
• Reaction rate is defined as the change in concentration of reactants or products per unit time
• Express the reaction rate for the general reaction aA + bB → cC + dD

  1️⃣ -1/a * Δ[A]/Δt

  2️⃣ -1/b * Δ[B]/Δt

  3️⃣ 1/c * Δ[C]/Δt

  4️⃣ 1/d * Δ[D]/Δt
• The standard units for reaction rate are M/s and mol L⁻¹ s⁻¹
• Higher reactant concentrations increase the likelihood of collisions
• What are the three key factors that affect reaction rate?

  Concentration, temperature, catalysts
• An increase of 10°C can double the reaction rate for many chemical reactions.
• What are the two main experimental methods to determine reaction rates?

  Initial Rate and Integrated Rate
• The mathematical expression for reaction rate includes stoichiometric coefficients.


  True
• The reaction rate can be expressed in terms of the change in concentration of any reactant or product.

  True