Rate Constant for Reaction A to C in Set of Two Parallel Reactions Calculator

Formula Used:

\[ k_2 = \frac{1}{t} \times \ln\left(\frac{A_0}{RA}\right) - k_1 \]

Time:

seconds

Initial Concentration of Reactant A:

mol/m³

Reactant A Concentration:

mol/m³

Reaction Rate Constant 1:

1/s

Reaction Rate Constant 2 (1/s):

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1. What is Rate Constant for Reaction A to C in Parallel Reactions?

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.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ k_2 = \frac{1}{t} \times \ln\left(\frac{A_0}{RA}\right) - k_1 \]

Where:

\( k_2 \) — Rate constant for reaction A → C (1/s)
\( t \) — Reaction time (seconds)
\( A_0 \) — Initial concentration of reactant A (mol/m³)
\( RA \) — Concentration of reactant A at time t (mol/m³)
\( k_1 \) — Rate constant for the parallel reaction A → B (1/s)

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.

3. Importance of Rate Constant Calculation

Details: Determining individual rate constants in parallel reactions is crucial for understanding reaction mechanisms, optimizing conditions, and predicting product distributions.

4. Using the Calculator

Tips: Enter the reaction time, initial concentration, current concentration, and the known rate constant (k₁). All concentrations must be in the same units.

5. Frequently Asked Questions (FAQ)

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.