Time Interval Formula:
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Definition: This calculator determines the time interval required for the reactant concentration to change from initial to final value in a first order reaction followed by a zero order reaction.
Purpose: It helps chemical engineers and researchers analyze reaction kinetics in multi-step reaction systems.
The calculator uses the formula:
Where:
Explanation: The natural log of the concentration ratio is divided by the rate constant to determine the time interval.
Details: Accurate time interval calculation is crucial for reaction optimization, process design, and safety analysis in chemical engineering.
Tips: Enter the rate constant (default 0.42 1/s), initial concentration (default 80 mol/m³), and final concentration (default 24 mol/m³). All values must be > 0 and initial concentration > final concentration.
Q1: What does the rate constant represent?
A: The rate constant (kI) indicates how fast the first order reaction proceeds.
Q2: Why must initial concentration be greater than final?
A: The reaction proceeds from higher to lower concentration; otherwise the calculation would give negative time.
Q3: What units should be used?
A: Use consistent units - seconds for time, mol/m³ for concentration, and 1/s for rate constant.
Q4: Can this be used for other reaction orders?
A: No, this formula is specific for first order followed by zero order reactions in series.
Q5: How does temperature affect the calculation?
A: Temperature affects the rate constant (kI), which should be determined at the relevant temperature.