3.1.9.2 Determination of Rate Equation

• What does a rate equation describe?

  Reaction rate and concentrations
• In a zero-order reaction, the rate is independent of reactant concentration.


  True
• In a first-order reaction, doubling the reactant concentration doubles the rate.


  True
• The initial rate method involves keeping the concentrations of all reactants constant except one.


  True
• The order of a reaction indicates how the rate changes with changes in reactant concentrations
• In a second-order reaction, the rate is proportional to the square of one reactant concentration
• When monitoring a reaction, changes in concentrations are observed over time.
• In a zero-order reaction, doubling the concentration of a reactant has no effect on the reaction rate.


  True
• Match the reactant with its contribution to the rate:

  Reactant A ↔️ $[A]^{m}$

  Reactant B ↔️ $[B]^{n}$
• The order of a reaction indicates how the rate changes with changes in reactant concentrations
• Match the order of reaction with its relationship between rate and concentration:

  Zero-order ↔️ Rate is independent of concentration

  First-order ↔️ Rate is proportional to concentration

  Second-order ↔️ Rate is proportional to the square of concentration
• What are reactants in a chemical reaction?

  Substances that undergo change
• Match the order of reaction with its effect on rate when reactant concentration is doubled:

  Zero-order ↔️ No effect on rate

  First-order ↔️ Rate doubles

  Second-order ↔️ Rate quadruples
• What is the relationship between rate and concentration in a zero-order reaction?

  Rate is independent
• What happens to the reaction rate in a zero-order reaction if the reactant concentration is doubled?

  Rate remains unchanged
• The initial rate method is used to determine the order of reactants in a rate equation.


  True
• What does the overall rate equation $Rate =$$k[A]^{m}[B]^{n}$ describe?


  Overall reaction rate
• Steps to calculate the rate constant $k$ from experimental data:


  1️⃣ Identify the rate equation

  2️⃣ Select a data set

  3️⃣ Substitute the values

  4️⃣ Solve for $k$
• Steps to determine the rate equation for a reaction

  1️⃣ Conduct experiments to measure reaction rates

  2️⃣ Analyze experimental data to determine orders of reactants

  3️⃣ Write the overall rate equation based on orders

  4️⃣ Determine the rate constant from data
• What is the rate equation for the reaction $A +$$B \rightarrow C$?


  $\text{Rate} =$$k[A][B]$
• In experiments to measure reaction rates, reactants are prepared at various concentrations
• How is the rate constant k</latex> calculated?

  $k =$$\frac{\text{Rate}}{[A][B]}$
• In a first-order reaction, the rate is proportional to one reactant concentration.

  True
• Steps to conduct experiments to measure reaction rates:

  1️⃣ Prepare the reactants

  2️⃣ Monitor the reaction

  3️⃣ Record the data

  4️⃣ Analyze the results
• What is the rate constant $k$ calculated from experimental data in the example provided?


  $1 \, M^{ - 1}s^{ - 1}$
• In the overall rate equation, $k$ represents the rate constant
• What is the rate constant $k$ calculated in the worked example given $Rate =$$k[A][B]^{2}$?


  $2 \, M^{ - 2} s^{ - 1}$