JEE Chemistry - MCQ Practice Questions

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?

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:

The rate constant for a reaction at 298 K is 2 × 10⁻⁵ s⁻¹ with Ea = 80 kJ/mol. What is the frequency factor (A) if rate = Ae^(-Ea/RT)?

In the reaction mechanism: (1) A + B ⇌ AB (fast), (2) AB + C → ABC (slow), the order predicted from this mechanism is:

In the complex reaction: A + B → I (fast equilibrium), I + B → C (slow), the rate law derived from this mechanism is:

For a reaction with Eₐ = 50 kJ/mol and A = 2 × 10¹³ s⁻¹ (Arrhenius pre-exponential factor), calculate k at 300K (R = 8.314 J/mol·K)

For the reaction: (1) Cl₂ ⇌ 2Cl (fast), (2) Cl + H₂ → HCl + H (slow), (3) H + Cl₂ → HCl + Cl (fast). The overall reaction is:

A reaction has Eₐ = 60 kJ/mol. How many times faster will it be at 327°C compared to 27°C? (R = 8.314 J/mol·K, assume A constant)