# Arrhenius Equation Calculator

The Arrhenius equation represents the fraction of collisions that have sufficient energy to overcome the activation barrier (i.e., have energy greater than or equal to the activation energy Ea) at a given temperature T. It is used to determine the effect of temperature on the rate of the reaction.

## What is an Arrhenius Equation Calculator?

The 'Arrhenius Equation Calculator' is a free online tool that calculates the rate constant in the Arrhenius equation for a reaction. In this calculator, you can enter the Activation Energy(Ea), Temperatur, Frequency factor and the rate constant will be calculated within a few seconds.

## How to Use Arrhenius Equation Calculator?

Follow the steps given below to use the calculator:

**Step 1:**Enter the known values in the space provided.**Step 2:**Click on the**"Calculate"**button to find the rate constant.**Step 3:**Click on**"Reset"**to clear the field and enter new values.

## How to Find an Arrhenius Equation?

According to Arrhenius, the rate constant of a reaction is dependent on Activation Energy(Ea), Temperatur and the Frequency factor and is given by the formula:

**K = A × e ^{[ - Ea / (R × T)]}**

Where K is the rate constant.

A is the Frequency Factor in sec^{-1}

Ea is the activation energy in KJ mol^{-1}

R is the universal gas constant.

And T is the temperature in Kelvin.

**Solved Example:**

Find the rate constant if the activation energy is 300 kj/mol and its frequency factor is 10 M^{-1}s^{-1} and the temperature is 450 K**?**

**Solution:**

Given: E_{a} = 300 kJ.mol^{-1} = 300000 J.mol^{-1}

A = 10 M^{-1}s^{-1}, ln(A) = 2.3 (approx.)

T = 450 K

ln k = ln(A) – (E_{a}/RT)

ln k = 2.3 – (300000 J.mol^{-1})/(8.314 J.mol^{-1}.K^{-1})*(450K)

ln k = 2.3 – 80.18

ln k = -77.88

k = 149847.31077 × 10^{-39} M^{-1}s^{-1}

Similarly, you can try the calculator and find the rate for the following:

Find the rate constant if the activation energy is 100 kj/mol and its frequency factor is 20 M^{-1}s^{-1} and the temperature is 350 K**?**

Find the rate constant if the activation energy is 150 kj/mol and its frequency factor is 5 M^{-1}s^{-1} and the temperature is 200 K**?**