The following diagrams represent mixtures of NO(g) and O2(𝑔). These two substances react as follows:
2 NO(𝑔)+O2(𝑔)⟶2 NO2(𝑔)
It has been determined experimentally that the rate is second order in NO and first order in O2. Based on this fact, which of the following mixtures will have the fastest initial rate? [Section 14.2]

Verified step by step guidance

1. <Identify the rate law for the reaction: The rate law is determined by the orders of the reactants. Since the reaction is second order in NO and first order in O2, the rate law can be expressed as: rate = k[NO]^2[O2].>
2. <Examine the given mixtures: Look at the diagrams provided for the concentrations of NO and O2 in each mixture.>
3. <Determine the initial rate for each mixture: Use the rate law to calculate the initial rate for each mixture by substituting the concentrations of NO and O2 into the rate law.>
4. <Compare the initial rates: The mixture with the highest calculated initial rate will have the fastest initial rate of reaction.>
5. <Select the mixture with the fastest initial rate: Based on your calculations, identify which mixture corresponds to the highest initial rate.>

Key Concepts

Reaction Order

Reaction order refers to the power to which the concentration of a reactant is raised in the rate law of a chemical reaction. In this case, the reaction is second order in NO and first order in O2, indicating that the rate of reaction depends quadratically on the concentration of NO and linearly on the concentration of O2. Understanding reaction order is crucial for predicting how changes in concentration affect the reaction rate.

Rate Law

The rate law expresses the relationship between the rate of a chemical reaction and the concentration of its reactants. For the given reaction, the rate law can be written as Rate = k[NO]^2[O2], where k is the rate constant. This equation allows us to calculate the initial rate of reaction based on the concentrations of NO and O2, which is essential for determining which mixture will react fastest.

Initial Rate of Reaction

The initial rate of reaction is the rate at which reactants are converted to products at the very beginning of the reaction, typically measured right after the reactants are mixed. It is influenced by the concentrations of the reactants and their respective orders in the rate law. Analyzing the initial rate helps in comparing different mixtures to identify which one will produce products most rapidly.