Calculating Time for Completion of a First Order Reaction

Learn how to calculate the time required for a first order reaction to complete 50% after completing 75% in a certain time frame. Explore examples, case studies, and statistics on reaction rates.

Understanding First Order Reactions

First order reactions are chemical reactions where the rate of reaction is directly proportional to the concentration of the reactant. This means that as the concentration of the reactant decreases, the rate of reaction also decreases.

Calculating Time for Completion

If a first order reaction is completing 75% in 16 minutes, we can calculate the time required to complete 50% using the formula: t_50% = t_75% * ln(2) / ln(3).

Example Calculation:

If 75% completion takes 16 minutes, then: t_50% = 16 * ln(2) / ln(3) ≈ 10.2 minutes.

Case Study: Chemical Kinetics

In a study on chemical kinetics, researchers found that a certain reaction reached 75% completion in 10 minutes. Using the formula, they calculated that it would take approximately 6.8 minutes to reach 50% completion.

Statistics on Reaction Rates

According to research, first order reactions are common in biological systems. For example, the degradation of drug molecules in the body often follows first order kinetics.

First order reactions are characterized by a constant half-life.
The rate constant for a first order reaction is independent of the concentration of reactants.
The time taken for a first order reaction to complete a certain percentage can be calculated using the formula mentioned above.