5.1.1 Rate equations

• What is a rate equation?

  Mathematical expression for reaction rate
• Changes in reactant concentrations can affect the reaction rate.


  True
• Why are both types of rate equations crucial?

  Analyze and predict reaction behavior
• Concentration terms in a rate equation are raised to their respective orders of reaction.


  True
• What is the relationship between rate and concentration in a zero-order reaction?

  Rate is independent of concentration
• What is the relationship between rate and concentration in a second-order reaction?

  Rate is proportional to [A]^2
• Rate equations help us understand the kinetics
• Match the type of rate equation with its definition:

  Empirical rate equation ↔️ Determined experimentally without mechanism

  Mechanistic rate equation ↔️ Derived from proposed reaction mechanism
• The rate constant (k) reflects the reaction's rate at a specific temperature
• Arrange the reaction orders from lowest to highest based on their dependence on reactant concentration:

  1️⃣ Zero-order

  2️⃣ First-order

  3️⃣ Second-order
• In a first-order reaction, the rate is directly proportional to the reactant concentration.


  True
• A first-order reaction suggests the rate-determining step involves the breakdown of a single molecule
• In a first-order reaction, the rate is proportional to the first power of the reactant concentration
• Sequence the steps for distinguishing between zero, first, and second-order reactions

  1️⃣ Measure the reaction rate at different reactant concentrations

  2️⃣ Analyze the relationship between rate and concentration

  3️⃣ Identify the order based on the observed relationship
• Match the reaction order with its definition:

  Zero-order ↔️ Rate is independent of concentration

  First-order ↔️ Rate is proportional to concentration

  Second-order ↔️ Rate is proportional to square of concentration
• What is a rate equation?

  Mathematical expression for rate
• Match the component of a rate equation with its definition:

  Rate constant (k) ↔️ Proportionality constant at specific temperature

  Concentration terms ↔️ Reactant concentrations raised to orders
• The order of a reaction describes how the reaction rate changes with reactant concentrations


  True
• What happens to the rate of a first-order reaction if the reactant concentration is doubled?

  Reaction rate doubles
• Doubling the reactant concentration in a second-order reaction increases the rate by a factor of four


  True
• Sequence the steps for determining the order of a reaction experimentally

  1️⃣ Measure reaction rate at different concentrations

  2️⃣ Analyze the relationship between rate and concentration

  3️⃣ Identify the reaction order
• What is the order of a reaction if doubling the reactant concentration doubles the reaction rate?

  First-order
• To calculate the rate constant for a first-order reaction, the formula is k = Rate / [A]
• What is the relationship between rate and concentration in a zero-order reaction?

  Rate is independent
• What is the rate equation for a second-order reaction?

  Rate = k[A]^2
• The rate of a zero-order reaction changes with reactant concentration

  False
• In a second-order reaction, the rate is proportional to the square of the reactant concentration
• An empirical rate equation is determined experimentally without regard to the reaction mechanism
• What does the rate constant reflect in a rate equation?

  Reaction speed at temperature
• Arrange the following reaction orders based on the impact of doubling reactant concentration on the reaction rate

  1️⃣ Zero-order (no change)

  2️⃣ First-order (doubles)

  3️⃣ Second-order (quadruples)
• In a first-order reaction, doubling the reactant concentration doubles the reaction rate
• Match the reaction order with an example:

  Zero-order ↔️ Decomposition of HI on gold surface

  First-order ↔️ Radioactive decay

  Second-order ↔️ Reaction of NO with ozone
• The order of a reaction is the power to which the reactant concentration is raised in the rate equation
• The rate constant (k) is a fixed value for all reactions at the same temperature

  False
• If the reaction rate is 0.05 M/s and the concentration of A is 0.01 M in a first-order reaction, what is the rate constant?

  5 s^-1