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Definition: This calculator determines the rate constant (k₂) for one of two parallel reactions (A → C) based on reaction time, concentration changes, and the other reaction's rate constant (k₁).
Purpose: It helps chemists and chemical engineers analyze parallel reaction kinetics and determine individual reaction rates.
The calculator uses the formula:
Where:
Explanation: The natural log of the concentration ratio gives the total rate of disappearance, from which we subtract the known rate constant to get the desired rate constant.
Details: Determining individual rate constants in parallel reactions is crucial for understanding reaction mechanisms, optimizing conditions, and predicting product distributions.
Tips: Enter the reaction time, initial concentration, current concentration, and the known rate constant (k₁). All concentrations must be in the same units.
Q1: What are parallel reactions?
A: Parallel reactions occur when a reactant can form different products through simultaneous reaction pathways.
Q2: Why use natural logarithm in the formula?
A: The natural log relates to the integrated rate law for first-order reactions, which this formula assumes.
Q3: What units should I use?
A: Time in seconds, concentrations in mol/m³ (or consistent units), rate constants in 1/s.
Q4: Can this be used for non-first-order reactions?
A: No, this formula specifically applies to first-order parallel reactions.
Q5: What if I get a negative rate constant?
A: Check your inputs - negative values suggest either measurement errors or that the assumed reaction mechanism may be incorrect.