AP Chemistry Questions on Reaction Rate: Test Your Knowledge

📚 Quick Study Guide

• ⏱️ Rate Law: Expresses how the rate of a reaction depends on the concentration of reactants. For a reaction $aA + bB \rightarrow cC + dD$, the rate law is often in the form: $rate = k[A]^m[B]^n$, where $k$ is the rate constant, and $m$ and $n$ are the orders of the reaction with respect to A and B, respectively.
• 🌡️ Factors Affecting Reaction Rate:
  • Concentration of reactants
  • Temperature (Arrhenius Equation: $k = Ae^{-\frac{E_a}{RT}}$)
  • Presence of a catalyst
  • Surface area (for heterogeneous reactions)
• 📈 Reaction Order:
  • Zero order: Rate is independent of reactant concentration.
  • First order: Rate is directly proportional to reactant concentration.
  • Second order: Rate is proportional to the square of the reactant concentration.
• 🔑 Rate Constant (k): A proportionality constant that relates the rate of reaction to the concentrations of reactants. It is temperature-dependent.
• 🤕 Activation Energy ($E_a$): The minimum energy required for a reaction to occur.

🧪 Practice Quiz

1. What is the effect of a catalyst on the rate of a chemical reaction?
   1. It increases the activation energy.
   2. It decreases the activation energy.
   3. It does not affect the activation energy.
   4. It shifts the equilibrium towards reactants.
2. For the reaction $2A + B \rightarrow C$, the rate law is given by rate = $k[A][B]^2$. What is the overall order of the reaction?
   1. 1
   2. 2
   3. 3
   4. 4
3. Which of the following factors does NOT affect the rate of a chemical reaction?
   1. Temperature
   2. Concentration of reactants
   3. Presence of a catalyst
   4. Color of reactants
4. The rate constant, $k$, is dependent on:
   1. Concentration
   2. Temperature
   3. Pressure
   4. Volume
5. If a reaction is first order in reactant A, what happens to the rate if the concentration of A is doubled?
   1. The rate remains the same.
   2. The rate is halved.
   3. The rate is doubled.
   4. The rate is quadrupled.
6. According to the Arrhenius equation, increasing the temperature will generally:
   1. Decrease the rate constant.
   2. Increase the rate constant.
   3. Not affect the rate constant.
   4. Decrease the activation energy.
7. Which of the following represents the correct rate law for an elementary reaction $A + B \rightarrow C$?
   1. Rate = $k[C]$
   2. Rate = $k[A] + k[B]$
   3. Rate = $k[A][B]$
   4. Rate = $k[A]^2[B]$