This calculator helps you determine the rate of a chemical reaction based on changes in concentration over time. The rate of reaction is typically expressed as the change in concentration of a reactant or product per unit of time.
Understanding the Rate of Reaction
The rate of a chemical reaction quantifies how quickly reactants are consumed or products are formed over a specific period. It's a fundamental concept in chemical kinetics, helping us understand reaction speeds and factors that influence them, such as temperature, concentration, and catalysts.
The most basic way to calculate the average rate of reaction is to measure the change in concentration of a reactant or product and divide it by the time interval over which that change occurred.
Formula:
Rate of Reaction = Δ[Concentration] / Δt
Where:
Δ[Concentration] represents the change in molar concentration (final concentration – initial concentration).
Δt represents the change in time (time elapsed).
The units for the rate of reaction are typically moles per liter per second (mol/L·s).
Example Calculation:
Consider a reaction where the concentration of a reactant decreases from 1.0 mol/L to 0.5 mol/L over a period of 60 seconds.
Initial Concentration = 1.0 mol/L
Final Concentration = 0.5 mol/L
Time Elapsed = 60 seconds
Using the formula:
Rate of Reaction = (0.5 mol/L – 1.0 mol/L) / 60 s
Rate of Reaction = -0.5 mol/L / 60 s
Rate of Reaction = -0.00833 mol/L·s
The negative sign indicates that the concentration of a reactant is decreasing. Often, the rate is reported as a positive value by considering the rate of product formation or by taking the absolute value of the rate of reactant disappearance.