Formula Used:
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Definition: The ratio compares the collision diameters and reduced masses of two different molecular collisions to determine their relative pre-exponential factors.
Purpose: This calculation is important in chemical kinetics to compare reaction rates between different molecular systems.
The calculator uses the formula:
Where:
Explanation: The ratio depends on the squares of the collision diameters and the square roots of the reduced masses.
Details: The pre-exponential factor is a key component in the Arrhenius equation that describes reaction rates. Comparing these factors helps predict relative reaction rates.
Tips: Enter the collision diameters (in meters) and reduced masses (in kg/mol) for both systems. All values must be positive numbers.
Q1: What is a collision diameter?
A: The distance between centers of two molecules at their closest approach during collision.
Q2: How is reduced mass calculated?
A: Reduced mass μ = (m₁ × m₂)/(m₁ + m₂), where m₁ and m₂ are the masses of the colliding molecules.
Q3: Why does diameter appear squared in the formula?
A: The collision cross-section (probability of collision) is proportional to the square of the collision diameter.
Q4: What does the ratio tell us?
A: It shows how much more likely collisions are in one system compared to another, all else being equal.
Q5: Can this be used for reactions with different temperatures?
A: This ratio only compares the pre-exponential factors. For complete rate comparisons, you would need to include the exponential (activation energy) terms.