Pharmacy Practice MCQ- Reaction Kinetics

Pharmacy Practice MCQ, in this article we will solve, Practice MCQ under subject physical pharmaceutics II. Read following article for your reference.

Reaction Kinetics: Zero-Order Reactions, Zero-Pseudo-Order Reactions, First-Order Reactions, Second-Order Reactions » PHARMACAREERS

For a zero-order reaction, the rate of reaction is:
- A. Directly proportional to reactant concentration
- B. Inversely proportional to reactant concentration
- C. Independent of reactant concentration
- D. Exponentially dependent on reactant concentration
In a zero-order reaction, if the initial concentration of the reactant is doubled, the rate of reaction:
- A. Remains the same
- B. Doubles
- C. Triples
- D. Decreases by half
The unit of the rate constant (k) for a zero-order reaction is:
- A. mol/L·s
- B. L/mol·s
- C. s⁻¹
- D. L²/mol·s
In a zero-order reaction, the plot of concentration vs. time is:
- A. Curved
- B. Exponential
- C. Linear
- D. Parabolic
Which of the following is a characteristic of a zero-order reaction?
- A. Reaction rate increases with increasing concentration
- B. Reaction rate is constant
- C. Reaction rate decreases with decreasing concentration
- D. Reaction rate varies exponentially with concentration

A pseudo-first-order reaction is a reaction that:
- A. Appears to be first-order under special conditions
- B. Is actually a second-order reaction
- C. Is independent of concentration
- D. Exhibits zero-order behavior
The term “pseudo-order” is used when:
- A. The reaction order is unknown
- B. The reaction mimics a different order under certain conditions
- C. The reaction occurs in multiple steps
- D. The reaction is irreversible
Which of the following can be considered a pseudo-first-order reaction?
- A. Hydrolysis of esters in the presence of excess water
- B. Decomposition of hydrogen peroxide
- C. Combustion reactions
- D. Polymerization reactions
In a pseudo-first-order reaction, the rate constant is:
- A. Dependent on the concentration of both reactants
- B. Dependent on the concentration of one reactant
- C. Independent of reactant concentrations
- D. Dependent on temperature only
The concept of pseudo-order reactions is particularly useful in:

A. Homogeneous catalysis
B. Heterogeneous catalysis
C. Analyzing complex reaction mechanisms
D. Simple reaction mechanisms

For a first-order reaction, the half-life (t₁/₂) is:

A. Proportional to the initial concentration
B. Independent of the initial concentration
C. Inversely proportional to the initial concentration
D. Doubles when concentration is halved

In a first-order reaction, if the concentration of the reactant is reduced by half, the rate of reaction:

A. Remains the same
B. Doubles
C. Halves
D. Quadruples

The rate constant (k) for a first-order reaction has units of:

A. mol/L·s
B. L/mol·s
C. s⁻¹
D. mol²/L²·s

The integrated rate law for a first-order reaction is:

A. [A]=[A]0e−kt[A] = [A]_0 e^{-kt}
B. [A]=[A]0−kt[A] = [A]_0 – kt
C. [A]=[A]0+kt[A] = [A]_0 + kt
D. [A]=[A]0kt[A] = [A]_0 \sqrt{kt}

The slope of the plot of ln[A] vs. time for a first-order reaction gives:

A. -k
B. k
C. 1/k
D. k²

The rate of a second-order reaction is proportional to:
- A. The square of one reactant concentration
- B. The sum of reactant concentrations
- C. The product of two reactant concentrations
- D. The inverse of one reactant concentration
The half-life (t₁/₂) of a second-order reaction is:
- A. Directly proportional to the initial concentration
- B. Inversely proportional to the initial concentration
- C. Independent of initial concentration
- D. Doubles when concentration is halved
The unit of the rate constant (k) for a second-order reaction is:
- A. mol/L·s
- B. L/mol·s
- C. L²/mol·s
- D. s⁻¹
For a second-order reaction, the integrated rate law is:
- A. 1[A]=1[A]0+kt\frac{1}{[A]} = \frac{1}{[A]_0} + kt
- B. [A]=[A]0e−kt[A] = [A]_0 e^{-kt}
- C. [A]=[A]0−kt[A] = [A]_0 – kt
- D. ln⁡[A]=ln⁡[A]0+kt\ln[A] = \ln[A]_0 + kt
The plot of 1/[A] vs. time for a second-order reaction is:
- A. Linear with a negative slope
- B. Linear with a positive slope
- C. Exponential
- D. Logarithmic

Which reaction order corresponds to a rate that is directly proportional to the square of the concentration of one reactant?
- A. Zero-order
- B. First-order
- C. Second-order
- D. Third-order
In a reaction mechanism, the slowest step is referred to as the:
- A. Rate-determining step
- B. Fast step
- C. Intermediate step
- D. Catalyst step
The Arrhenius equation relates the rate constant (k) to:
- A. Temperature and activation energy
- B. Concentration and pressure
- C. Volume and pressure
- D. Enthalpy and entropy
The collision theory of reaction rates depends on:
- A. The frequency of effective collisions
- B. The concentration of the reactants
- C. The temperature of the reaction
- D. All of the above
Catalysts increase the rate of a chemical reaction by:
- A. Increasing the temperature
- B. Lowering the activation energy
- C. Increasing the concentration of reactants
- D. Changing the equilibrium constant
In a reaction where the rate is found to be independent of the concentration of one of the reactants, the order with respect to that reactant is:
- A. Zero
- B. One
- C. Two
- D. Three
The rate law for the reaction 2A + B → C is found to be rate = k[A]²[B]. What is the overall order of the reaction?
- A. Zero
- B. One
- C. Two
- D. Three
A reaction has a half-life that is independent of the initial concentration of reactants. This reaction is:
- A. Zero-order
- B. First-order
- C. Second-order
- D. Third-order
For a reaction with the rate law rate = k[A][B]², what is the effect on the rate if the concentration of A is doubled and the concentration of B is kept constant?
- A. The rate doubles
- B. The rate triples
- C. The rate quadruples
- D. The rate remains the same
In a first-order reaction, the concentration of the reactant decreases exponentially with time. The mathematical expression for this is:
- A. [A]=[A]0e−kt[A] = [A]_0 e^{-kt}
- B. [A]=[A]0−kt[A] = [A]_0 – kt
- C. [A]=[A]0+kt[A] = [A]_0 + kt
- D. [A]=[A]0/(1+kt)

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