Consider the mixture of ethanol, C2H5OH, and O2 shown in the accompanying diagram. (c) How many molecules of CO2, H2O, C2H5OH, and O2 will be present if the reaction goes to completion?

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 many molecules of each substance will be present after a reaction goes to completion.

Balancing Chemical Equations

Balancing chemical equations is the process of ensuring that the number of atoms for each element is the same on both sides of the equation. This is crucial for accurately representing the conservation of mass during a chemical reaction. In the context of the given question, balancing the equation for the combustion of ethanol will provide the necessary ratios to calculate the amounts of CO2, H2O, C2H5OH, and O2 produced or consumed.

Limiting Reactant

The limiting reactant is the substance that is completely consumed first in a chemical reaction, thus determining the maximum amount of product that can be formed. Identifying the limiting reactant is vital for calculating the final quantities of products and remaining reactants after the reaction has gone to completion. In the case of the ethanol and O2 mixture, knowing which reactant limits the reaction will help in determining the final amounts of CO2 and H2O produced.