JEE Chemistry - MCQ Practice Questions

The rate of a chemical reaction is defined as the change in concentration of reactants or products per unit time. Which of the following is NOT a factor affecting reaction rate?

The half-life of a zero-order reaction is:

A reaction has a rate constant of k = 2.5 × 10⁻⁴ s⁻¹ at 298 K. What is the order of this reaction if the units of k are s⁻¹?

Which of the following statements about activation energy (Eₐ) is correct?

For a first-order reaction, if the initial concentration is [A]₀ = 0.5 M and after 30 seconds it becomes 0.25 M, what is the rate constant?

The mechanism of a reaction is: Step 1: A + B → C (slow), Step 2: C + D → E + F (fast). What is the overall reaction and the rate law?

Which of the following graphs represents a first-order reaction?

According to Arrhenius equation, k = Ae^(-Eₐ/RT), a catalyst increases reaction rate by:

For the reaction A → B, the integrated rate law for zero-order kinetics is:

At 300 K, a reaction has a half-life of 10 minutes. At 310 K, the half-life becomes 5 minutes. What is the approximate value of temperature coefficient (assuming RRT ≈ 2)?

If a reaction is first-order with rate constant k = 0.1 min⁻¹, what fraction of the reactant remains after 5 half-lives?

For a reaction with mechanism: A ⇌ B (fast equilibrium), B + C → D (slow), the rate law is:

The rate constant for a reaction increases 4 times when temperature increases from 27°C to 47°C. What is the activation energy? (R = 8.314 J mol⁻¹ K⁻¹)

In a reaction, the rate increases by a factor of 8 when [A] doubles and by a factor of 2 when [B] doubles. What is the overall order of the reaction?

For the consecutive reaction A → B → C, if the rate constants are k₁ = 0.1 s⁻¹ and k₂ = 0.05 s⁻¹, and k₁ > k₂, which statement is true?

The collision theory of reaction rates explains that a reaction occurs when molecules collide with:

In the Lindemann mechanism for unimolecular reactions, A* represents an activated molecule. The rate-determining step is:

For a pseudo-first-order reaction where [B]₀ >> [A]₀, the rate law simplifies to first-order even though the actual order is higher. This is because:

Which of the following is an example of a homogeneous catalyst?

A reaction has activation energy of 50 kJ/mol. If the temperature is increased from 300 K to 310 K, the rate constant increases by a factor of approximately (R = 8.314 J/mol·K):