Initial Reactant Concentration by Intermediate Conc. for Zero Order followed by First Order Rxn Calculator

Formula Used:

\[ C_{A0} = \frac{C_R}{\frac{1}{K} \times (1 - e^{-(k_1 \times \Delta t)})} \]

Intermediate Concentration (C_R):

mol/m³

Overall Rate of Reaction (K):

mol/(m³·s)

Rate Constant (k₁):

mol/(m³·s)

Time Interval (Δt):

seconds

Initial Concentration (C_A0): mol/m³

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1. What is Initial Reactant Concentration Calculator?

Definition: This calculator determines the initial concentration of reactant in a series reaction where the first step is zero order followed by a first order reaction.

Purpose: It helps chemical engineers and researchers analyze reaction kinetics and determine initial conditions for series reactions.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ C_{A0} = \frac{C_R}{\frac{1}{K} \times (1 - e^{-(k_1 \times \Delta t)})} \]

Where:

\( C_{A0} \) — Initial concentration of reactant (mol/m³)
\( C_R \) — Intermediate concentration (mol/m³)
\( K \) — Overall rate of reaction (mol/(m³·s))
\( k_1 \) — Rate constant for first order step (mol/(m³·s))
\( \Delta t \) — Time interval (seconds)

Explanation: The formula accounts for the exponential decay in concentration during the first order step and the relationship between the zero and first order rates.

3. Importance of Initial Concentration Calculation

Details: Accurate determination of initial concentration is crucial for reaction design, process optimization, and kinetic studies in chemical engineering.

4. Using the Calculator

Tips: Enter the intermediate concentration, overall rate of reaction (default 1.593), rate constant (default 0.07), and time interval (default 3). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is the physical meaning of the intermediate concentration?
A: It represents the concentration of the product formed in the first step that becomes the reactant for the second step.

Q2: How is the overall rate of reaction determined?
A: It's typically the ratio of the zero order rate constant to the first order rate constant.

Q3: What units should be used for the rate constant?
A: For first order reactions, the units should be mol/(m³·s) when using this formula.

Q4: Can this calculator be used for other reaction orders?
A: No, this specific formula applies only to zero order followed by first order series reactions.

Q5: What if I get negative values?
A: Check your inputs - all values must be positive. Negative concentrations are physically impossible.