1. What is Rate Constant for First Order Reaction?

Definition: The Rate Constant for First Order Reaction is defined as the rate of the reaction divided by the concentration of the reactant.

Purpose: This calculator helps determine the rate constant for first-order reactions in mixed flow reactors based on space time and reactant conversion.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( k' \) — Rate Constant for First Order Reaction (s⁻¹)
• \( \tau_{mixed} \) — Space Time in Mixed Flow (seconds)
• \( X_{mfr} \) — Reactant Conversion in Mixed Flow (0 to 1)

Explanation: The formula relates the reaction rate constant to the space time and the degree of reactant conversion in a mixed flow reactor.

3. Importance of Rate Constant Calculation

Details: Knowing the rate constant is crucial for reactor design, process optimization, and predicting reaction behavior under different conditions.

4. Using the Calculator

Tips: Enter the space time in seconds and the reactant conversion as a decimal between 0 and 1. Space time must be > 0 and conversion must be ≥ 0 and < 1.

5. Frequently Asked Questions (FAQ)

Q1: What is space time in a mixed flow reactor?
A: Space time is the time necessary to process one reactor volume of fluid at entrance conditions.

Q2: Why does the conversion need to be less than 1?
A: The formula becomes undefined at 100% conversion (X=1) because complete conversion would require infinite time in a mixed flow reactor.

Q3: What are typical units for the rate constant?
A: For first-order reactions, the rate constant has units of reciprocal time (typically s⁻¹).

Q4: How does this differ from plug flow reactors?
A: Mixed flow reactors have different conversion characteristics due to complete mixing, resulting in a different relationship between conversion and space time.

Q5: Can I use this for higher-order reactions?
A: No, this formula is specific to first-order reactions. Different equations apply for other reaction orders.