Concentration (Molarity – mol/L)
Mass (grams)
Volume of Gas (cm³)
Seconds (s)
Minutes (min)
Hours (hr)
Calculated Rate of Reaction
0.000
mol/(L·s)
How to Calculate Rate of Reaction Formula
The rate of reaction is a measure of how quickly reactants turn into products in a chemical reaction. Understanding reaction kinetics is crucial for controlling industrial processes, analyzing biological systems, and improving safety in chemical handling. This calculator helps you determine the average speed of a reaction over a specific time period.
The General Formula
The fundamental formula for calculating the average rate of reaction is based on the change in the amount of a substance divided by the time it took for that change to occur.
Rate = Δ Quantity / Δ Time
Rate = (Final Value – Initial Value) / Time Elapsed
In most introductory chemistry contexts, the rate is expressed as a positive value. If you are measuring the disappearance of a reactant, the change is negative, but we typically take the absolute magnitude for the rate.
Variables Used in Calculation
Quantity Change (Δ): This can be measured in Molarity (mol/L) for solutions, Mass (g) for solids, or Volume (cm³) for gases.
Time (t): The duration over which the reaction is observed, usually measured in seconds (s) or minutes (min).
Step-by-Step Calculation Example
Let's assume we are monitoring the decomposition of Hydrogen Peroxide. We measure the concentration of H₂O₂.
Identify Initial Value: At t=0s, the concentration is 1.00 mol/L.
Identify Final Value: At t=60s, the concentration is 0.75 mol/L.
Calculate Change: |0.75 – 1.00| = 0.25 mol/L.
Divide by Time: 0.25 mol/L / 60 s = 0.00417 mol/(L·s).
Factors Affecting Rate of Reaction
According to collision theory, several factors influence how fast a reaction proceeds: