Nitrogen monoxide and oxygen react to form nitrogen dioxide. Consider the mixture of NO and O2 shown in the accompanying diagram. The blue spheres represent N, and the red ones represent O. (c) If the actual yield of the reaction was 75% instead of 100%, how many molecules of each kind would be present after the reaction was over?

Verified step by step guidance

1. Identify the balanced chemical equation for the reaction: 2NO + O_2 \rightarrow 2NO_2.
2. Count the initial number of NO and O_2 molecules from the diagram.
3. Determine the limiting reactant by comparing the mole ratio of NO to O_2 based on the balanced equation.
4. Calculate the theoretical yield of NO_2 molecules using the limiting reactant.
5. Adjust the theoretical yield by multiplying it by the actual yield percentage (75%) to find the actual number of NO_2 molecules formed.

Key Concepts

Stoichiometry

Stoichiometry is the branch of chemistry that deals with the quantitative relationships between the reactants and products in a chemical reaction. It allows us to calculate the amounts of substances consumed and produced in a reaction based on balanced chemical equations. Understanding stoichiometry is essential for determining how much of each reactant is needed and how much product can be formed.

Percent Yield

Percent yield is a measure of the efficiency of a chemical reaction, calculated by comparing the actual yield of a product to the theoretical yield. The theoretical yield is the maximum amount of product that could be formed from given amounts of reactants, while the actual yield is what is obtained from the experiment. A percent yield of less than 100% indicates that not all reactants were converted into products.

Molecular Representation

Molecular representation involves using symbols and models to depict the composition and structure of molecules. In the context of the question, blue spheres represent nitrogen atoms and red spheres represent oxygen atoms, which helps visualize the reactants and products in the reaction. Understanding molecular representation is crucial for interpreting chemical reactions and predicting the outcome based on the quantities of reactants.