Question

The oxides of nitrogen are very important components in urban air pollution. Name each of the following compounds: (a) \(\mathrm{N}_{2} \mathrm{O},(\mathrm{b}) \mathrm{NO},(\mathrm{c}) \mathrm{NO}_{2},(\mathrm{~d}) \mathrm{N}_{2} \mathrm{O}_{5},(\mathrm{e}) \mathrm{N}_{2} \mathrm{O}_{4} .\)

Short answer

The names of the nitrogen oxide compounds are: a) \(\mathrm{N}_{2}\mathrm{O}\) : Dinitrogen Monoxide b) \(\mathrm{NO}\) : Nitrogen Monoxide c) \(\mathrm{NO}_{2}\) : Nitrogen Dioxide d) \(\mathrm{N}_{2}\mathrm{O}_{5}\) : Dinitrogen Pentoxide e) \(\mathrm{N}_{2}\mathrm{O}_{4}\) : Dinitrogen Tetroxide

Step-by-step solution

Naming \(\mathrm{N}_{2}\mathrm{O}\)

To name this compound, we need to count the number of Nitrogen (N) and Oxygen (O) atoms. There are 2 Nitrogen atoms and 1 Oxygen atom in the molecule. Following the nomenclature rules, we use the Greek prefix "di" to indicate 2 Nitrogens and the prefix "mono" to indicate 1 Oxygen. Thus, the name of this compound is dinitrogen monoxide.

Naming \(\mathrm{NO}\)

This time, we have 1 Nitrogen atom and 1 Oxygen atom in the molecule. To indicate 1 Nitrogen atom and 1 Oxygen atom in the compound, we use the Greek prefixes "mono" for Nitrogen and "mono" for Oxygen. However, the prefix "mono" is not used for the first element mentioned. So, the name of this compound is nitrogen monoxide.

Naming \(\mathrm{NO}_{2}\)

In this case, there is 1 Nitrogen atom and 2 Oxygen atoms. So, we indicate 1 Nitrogen atom by mentioning it first without any prefix, and for 2 Oxygen atoms, we use the prefix "di". Thus, the name of this compound is nitrogen dioxide.

Naming \(\mathrm{N}_{2}\mathrm{O}_{5}\)

Now, there are 2 Nitrogen atoms and 5 Oxygen atoms in the molecule. We use the prefix "di" to indicate 2 Nitrogens and "penta" to indicate 5 Oxygen atoms. Hence, the name of this compound is dinitrogen pentoxide.

Naming \(\mathrm{N}_{2}\mathrm{O}_{4}\)

Finally, we have 2 Nitrogen atoms and 4 Oxygen atoms in this compound. We use the prefix "di" to indicate 2 Nitrogens and "tetra" to indicate 4 Oxygen atoms. Thus, the name of this compound is dinitrogen tetroxide. In summary, the names of the nitrogen oxide compounds are: a) \(\mathrm{N}_{2}\mathrm{O}\) : Dinitrogen Monoxide b) \(\mathrm{NO}\) : Nitrogen Monoxide c) \(\mathrm{NO}_{2}\) : Nitrogen Dioxide d) \(\mathrm{N}_{2}\mathrm{O}_{5}\) : Dinitrogen Pentoxide e) \(\mathrm{N}_{2}\mathrm{O}_{4}\) : Dinitrogen Tetroxide

Key concepts

Chemical Nomenclature

Understanding chemical nomenclature is essential for students and professionals in chemistry. It allows us to systematically name chemical compounds based on their composition, providing a universal language for scientists. In the context of nitrogen oxides, nomenclature involves the usage of Greek prefixes to denote the number of atoms present in the compound. For instance, the prefix 'mono-' indicates one atom, while 'di-' represents two atoms.

Let's consider the examples from the exercise. The compound (N_{2}O) is named 'dinitrogen monoxide' because it has two nitrogen atoms and one oxygen atom. It's important to note that when there is only one atom of the first element, its prefix is usually omitted. Hence, NO is called 'nitrogen monoxide' rather than 'mononitrogen monoxide'. This simplicity helps avoid redundancy. Nomenclature also emphasizes the order of elements, starting with the less electronegative (usually the nonmetal) followed by the more electronegative element (often a halogen or oxygen).

By mastering the rules of chemical nomenclature, you can communicate complex chemical formulas clearly and accurately.

Oxidation States in Compounds

The oxidation state, or oxidation number, reflects the degree of oxidation of an element in a chemical compound. It's a key concept in redox reactions, where electrons are transferred between species, and is pivotal in determining the formula of compounds and their nomenclature.

In nitrogen oxides, the nitrogen atom can have various oxidation states, from +1 in N_{2}O to +4 in N_{2}O_{4}. Recognizing these states is made simpler by a few rules. For example, oxygen typically has an oxidation state of -2. Using this, one can deduce that in nitrogen dioxide (NO_{2}), with one nitrogen and two oxygen atoms, nitrogen has a +4 oxidation state since each oxygen contributes -2.

Understanding how oxidation states correlate with compound names can aid in predicting reactions and chemical behavior. For instance, compounds with higher oxidation states of nitrogen are generally more reactive, a fact that is crucial in fields such as environmental chemistry and material science.

Air Pollution Chemistry

Air pollution chemistry is a branch of environmental science that studies the chemical processes and compounds, like nitrogen oxides, in the atmosphere that contribute to pollution. Nitrogen oxides are significant air pollutants primarily produced by vehicle exhausts and industrial emissions.

The various nitrogen oxides have different roles in the atmosphere. Nitrogen dioxide (NO_{2}), for example, contributes to smog formation and can react with water to form acid rain, having major environmental and health impacts. Dinitrogen tetroxide (N_{2}O_{4}), on the other hand, is used as an aerospace propellant, but its decomposition in the atmosphere can contribute to ozone layer depletion.

Educators often encourage students to explore the roles these compounds play in both natural and human-made processes. Through this, students can understand how chemical knowledge is applied in policy making and environmental management to reduce air pollution and its associated risks.