Intermediate Concentration for First Order followed by Zero Order Reaction Calculator

Formula:

\[ C_{R,1st\ order} = C_{A0} \times \left(1 - e^{-k_I \times \Delta t} - \frac{k_0 \times \Delta t}{C_{A0}}\right) \]

Initial Reactant Concentration (CA0):

mol/m³

Rate Constant for First Step (kI):

1/s

Rate Constant for Zero Order (k0):

mol/m³·s

Time Interval (Δt):

Intermediate Concentration (CR):

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1. What is Intermediate Concentration for First Order followed by Zero Order Reaction?

Definition: This calculator determines the intermediate concentration in a series reaction where the first step is first order and the second step is zero order.

Purpose: It helps chemical engineers and researchers analyze reaction kinetics in multi-step processes.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ C_{R} = C_{A0} \times \left(1 - e^{-k_I \times \Delta t} - \frac{k_0 \times \Delta t}{C_{A0}}\right) \]

Where:

\( C_{R} \) — Intermediate concentration (mol/m³)
\( C_{A0} \) — Initial reactant concentration (mol/m³)
\( k_I \) — Rate constant for first order step (1/s)
\( k_0 \) — Rate constant for zero order step (mol/m³·s)
\( \Delta t \) — Time interval (s)

Explanation: The formula accounts for the first-order decay of the reactant and the zero-order formation of the intermediate.

3. Importance of This Calculation

Details: Accurate intermediate concentration calculations are crucial for reaction optimization, process design, and safety assessments in chemical engineering.

4. Using the Calculator

Tips: Enter all required parameters with correct units. Initial concentration must be positive, while rate constants and time must be non-negative.

5. Frequently Asked Questions (FAQ)

Q1: What does a negative result mean?
A: Negative values indicate the calculation is not physically meaningful, possibly due to invalid input parameters.

Q2: How do I determine the rate constants?
A: Rate constants are typically determined experimentally or from literature values for specific reactions.

Q3: What's the difference between first and zero order reactions?
A: First order depends on reactant concentration, while zero order proceeds at a constant rate regardless of concentration.

Q4: Can this be used for other reaction orders?
A: No, this calculator is specifically for first-order followed by zero-order reactions in series.

Q5: What time units should I use?
A: Use seconds for consistency with the rate constant units (1/s for kI).