The depletion of ozone \(\left(\mathrm{O}_{3}\right)\) in the stratosphere has been a matter of great concern among scientists in recent years. It is believed that ozone can react with nitric oxide (NO) that is discharged from the high-altitude jet plane, the SST. The reaction is $$ \mathrm{O}_{3}+\mathrm{NO} \longrightarrow \mathrm{O}_{2}+\mathrm{NO}_{2} $$ If \(0.740 \mathrm{~g}\) of \(\mathrm{O}_{3}\) reacts with \(0.670 \mathrm{~g}\) of \(\mathrm{NO}\), how many grams of \(\mathrm{NO}_{2}\) will be produced? Which compound is the limiting reagent? Calculate the number of moles of the excess reagent remaining at the end of the reaction.

Stratospheric ozone depletion refers to the reducing concentrations of ozone in the Earth's stratosphere, an effect caused by various man-made chemicals, such as chlorofluorocarbons (CFCs). This depletion creates what is commonly known as the 'ozone hole,' which leads to increased ultraviolet (UV) radiation reaching the Earth's surface, with harmful effects on living organisms, including skin cancer in humans and damage to crops and marine ecosystems.

Ozone depletion occurs when ozone reacts with certain substances, like nitric oxide (NO), which can be naturally occurring or a result of human activities. The given exercise presents a real-world scenario where ozone reacts with NO emitted by high-altitude jets, leading to the formation of nitrogen dioxide (NO2), a component of smog that can have detrimental effects on respiratory health.

Stoichiometric calculations are essential in quantitative chemical analysis, helping predict the outcomes of chemical reactions. They involve the use of the mole concept, balanced chemical equations, and the molar masses of substances to convert between mass, moles, and numbers of molecules or atoms. These calculations allow scientists and engineers to determine reactant consumption, product yields, and the limiting reagent—the reactant that will be completely consumed first and thus determines the extent of the reaction.

The exercise demonstrates a stoichiometric calculation by seeking to identify the limiting reagent between ozone (O3) and nitric oxide (NO) and calculating the number of grams of nitrogen dioxide (NO2) produced. This application of stoichiometry is not only pivotal in laboratory settings but also in industrial processes and environmental monitoring.

The mole concept is central to understanding chemical reactions at the microscopic level. A mole is a unit in chemistry that represents Avogadro's number (approximately 6.022 x 10²³) of atoms, molecules, or ions. It bridges the gap between the atomic scale and the macroscopic world we measure in the laboratory, allowing chemists to count particles by weighing them.

When we say that a substance has a molar mass of 48 g/mol, like ozone (O3) in the given exercise, we are stating that one mole of ozone molecules has a mass of 48 grams. By comparing the mass of a sample to the molar mass, we can calculate the number of moles present. This forms the basis of stoichiometric calculations and is vital for determining the proportions of reactants and products in a chemical reaction.

Balancing chemical equations is a fundamental skill in chemistry that ensures the law of conservation of mass is upheld in any given chemical reaction. In a balanced chemical equation, the number of atoms of each element is the same on both sides of the equation, which signifies that matter cannot be created or destroyed during the reaction.

The equation in the exercise, \( O_{3} + NO \longrightarrow O_{2} + NO_{2} \), represents a balanced reaction where one molecule of ozone reacts with one molecule of nitric oxide to produce one molecule of oxygen and one molecule of nitrogen dioxide. Through the process of balancing reactions, we establish the stoichiometric coefficients that are crucial for stoichiometric calculations, including determining the limiting reagent, which dictates the maximum amount of product that can be formed from given reactants.