Initial rate

Definition

The initial rate is the instantaneous rate of reaction at the very beginning when the reactants are first mixed. It is determined by measuring the change in concentration of a reactant or product over a short time period immediately after the reaction starts.

5 Must Know Facts For Your Next Test

1. The initial rate is typically measured when the concentration of reactants is highest.
2. It can be calculated using the slope of a tangent to the concentration vs. time curve at time zero.
3. The initial rate method helps determine reaction orders and rate constants.
4. Initial rates are often used in experiments where precise measurements are needed for kinetic analysis.
5. A plot of initial rates vs. concentrations can help derive the rate law for a reaction.

Review Questions

• What does the initial rate of a chemical reaction represent?
• How can you experimentally determine the initial rate?
• Why is it important to measure the initial rate rather than a later rate?

Related terms

Rate Law: An equation that relates the reaction rate to the concentrations of reactants.

Reaction Order: The power to which the concentration of a reactant is raised in the rate law.

Rate Constant: A proportionality constant in the rate law that is specific to a particular reaction at a given temperature.