Final answer:
To determine the order of a reaction, information on how the rate and half-life change with concentration is needed. The data provided suggests a more complex reaction, potentially second-order or higher, but additional information is required for a definitive determination.
Step-by-step explanation:
To determine the order of a reaction based on the given information, we need to use the concept of half-life and reaction rates. A reaction's order can be figured out by how its rate and half-life change with concentration. In a first-order reaction, the half-life is constant and doesn't depend on the initial concentration. For second-order reactions, the half-life increases as the reactant concentration decreases. As for zero-order reactions, the rate is independent of the concentration of reactants.
If 50% of the reaction occurs in 100 seconds, we can consider this as a half-life for the reaction. When 75% of the reaction occurs in 200 seconds, we are looking at one and a half half-lives. Based on this information, we can deduce that the reaction is likely not zero-order because the percentage completion is changing with time. It seems inconsistent with first-order kinetics as well because the time to achieve each successive 25% completion of the reaction should remain the same. Therefore, the provided data suggests a reaction that is more complex, potentially second order or higher. Without additional information or specific rate laws, the exact order cannot be confidently determined.
References to percent completion indicate that for a first-order reaction, 100% completion is reached after 10 half-lives. But the initial question of determining the order of reaction from the given percentages and times cannot be resolved with the information provided alone. Typically, to determine the order of a reaction, one needs either a series of concentration and time data points, or concentration and rate data points to analyze.