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Reaction Rate Ratio Calculator – Free Kinetics Tool

Advanced Reaction Rate Ratio Calculator

Calculate reaction rate ratios using the rate law Rate = k[A]^m[B]^n to compare relative reaction rates between experiments or determine reaction orders without knowing the rate constant (k). Input concentrations and orders for two experiments, and optionally a third for comparison.

Enter Experiment Parameters

Reaction Name:

[A]₁ (M):

[B]₁ (M):

Rate₁ (optional, M/s):

[A]₂ (M):

[B]₂ (M):

Rate₂ (optional, M/s):

Order of A (m, optional):

Order of B (n, optional):

Add Comparison Experiment (Optional) ▼

Comparison Reaction Name:

[A]₃ (M):

[B]₃ (M):

Rate₃ (optional, M/s):

Order of A (m, optional):

Order of B (n, optional):

Display Mode:

Standard

Step Details

Chart

Result

Calculation Details

Reaction Rate Comparison

Formulas

Reaction Rate Ratio Calculation

Reaction rate ratios are calculated using the rate law:

Rate = k[A]^m[B]^n

Ratio of rates between two experiments:

Rate₁ / Rate₂ = ([A]₁^m [B]₁^n) / ([A]₂^m [B]₂^n)

To find reaction order (e.g., m) when [B] is constant:

m = log(Rate₁ / Rate₂) / log([A]₁ / [A]₂)

Where:

Rate: Reaction rate (M/s).
k: Rate constant (cancels out in ratio).
[A], [B]: Molar concentrations of reactants (M).
m, n: Reaction orders for A and B.

Usage Notes:

Provide concentrations for at least two experiments.
Rate inputs are optional; if provided, orders can be calculated.
Order inputs are optional; if provided, rate ratios are computed.
Results are rounded to 4 decimal places for ratios and orders.
Comparison experiment enables additional rate analysis.

How to Use the Reaction Rate Ratio Calculator

Enter Reaction Name: Provide the reaction formula or name.
Input Experiment Parameters: Enter concentrations of reactants A and B for two experiments, and optionally their rates.
Specify Reaction Orders (Optional): Provide m and n if known, or leave blank to calculate them from rates.
Add Comparison Experiment (Optional): Include a third experiment for additional rate comparison.
Choose Display Mode: Select standard, step-by-step, or chart view.
Calculate: Click “Calculate” to compute rate ratios or orders.
Export Results (Optional): Download as JSON for further analysis.
Reset Data: Click “Reset” to clear fields.

FAQs (Frequently Asked Questions)

What is a reaction rate ratio?

A reaction rate ratio compares the rates of a reaction under different conditions, using the rate law Rate = k[A]^m[B]^n, by dividing the rate expressions of two experiments.

How do I determine reaction order?

By keeping one reactant’s concentration constant and varying another, the ratio of rates and concentrations can be used to calculate the order (e.g., m = log(Rate₁/Rate₂) / log([A]₁/[A]₂)).

Why does the rate constant (k) cancel out?

The rate constant cancels in the ratio Rate₁/Rate₂ if the temperature is constant across experiments, as k is the same in both rate laws.

What are typical units for concentrations and rates?

Concentrations are typically in mol/L (M), and rates for first-order reactions are in M/s. Units depend on the reaction order.

Where can I find experimental data for concentrations and rates?

Data can be obtained from lab experiments, chemical kinetics studies, or databases like the NIST Kinetics Database.