Question

The rate of homogeneous reaction is a function of:

• A. Pressure and composition only
• B. Temperature and pressure only
• C. Composition and temperature only
• D. Temperature, pressure and composition

Hint:

For homogeneous reactions, remember that \textbf{temperature}, \textbf{pressure}, and \textbf{composition} all influence the reaction rate.

Answer 1

The Correct Option is D

Step 1: Understanding Homogeneous Reactions
A homogeneous reaction occurs in a single phase (usually gas or liquid). The rate of such a reaction depends on how frequently the reactant molecules collide and how energetically they do so. Step 2: Key Factors Affecting Rate
The reaction rate \( r \) of a homogeneous reaction depends on:
Temperature: Influences the kinetic energy and activation energy barrier (Arrhenius equation).
Pressure: Especially for gaseous systems, increasing pressure increases concentration and thus the collision frequency.
Composition: The concentration of the reacting species directly impacts the reaction rate (as seen in rate laws like \( r = k[A]^m[B]^n \)). Step 3: Evaluating Options
Only option (D) includes all three relevant variables: temperature, pressure, and composition. The other options omit one of the key parameters. Conclusion: The rate of a homogeneous reaction is a function of temperature, pressure, and composition.