Half-life of reactions Knowledge-Based Download PDF

Questions

1. 1.

   A first-order reaction has a half-life of 24.0 min. If the initial concentration of the reactant is 0.640 M, what is the concentration of the reactant remaining after 96.0 min?

   • A) 0.160 M
   • B) 0.080 M
   • C) 0.020 M
   • D) 0.040 M
2. 2.

   For a second-order reaction $A \rightarrow \text{products}$, the initial concentration of $A$ is 0.80 M and its first half-life is 50 s. What is the duration of the second half-life for this reaction?

   • A) 25 s
   • B) 50 s
   • C) 75 s
   • D) 100 s
3. 3.

   A reaction $A \rightarrow B$ follows zero-order kinetics with a rate constant of 0.020 M/s. If the reaction begins with an initial concentration of $A$ equal to 1.2 M, what is the half-life of the reaction?

   • A) 15 s
   • B) 30 s
   • C) 60 s
   • D) 120 s
4. 4.

   A first-order decomposition reaction has a rate constant of $1.386 \times 10^{-2}\text{ s}^{-1}$ at a specific temperature. What is the half-life of this reaction?

   • A) 25 s
   • B) 50 s
   • C) 72 s
   • D) 100 s
5. 5.

   For a certain chemical reaction, doubling the initial reactant concentration causes the half-life of the reaction to be halved. What is the order of the reaction with respect to this reactant?

   • A) Zero order
   • B) First order
   • C) Second order
   • D) Third order