Question

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

Short answer

The names of the given nitrogen oxide compounds are: (a) N2O: Dinitrogen monoxide (nitrous oxide) (b) NO: Nitrogen monoxide (nitric oxide) (c) NO2: Nitrogen dioxide (d) N2O5: Dinitrogen pentoxide (e) N2O4: Dinitrogen tetroxide

Step-by-step solution

Determine the oxidation states of nitrogen in each compound

For each compound, we can find the oxidation state of nitrogen by considering the oxidation state of oxygen (-2) and using the formula for the oxidation state in each compound: (a) N2O: the oxidation state must be +1 because 2x(+1) + 1x(-2) = 0 (b) NO: the oxidation state must be +2 because 1x(+2) + 1x(-2) = 0 (c) NO2: the oxidation state must be +4 because 1x(+4) + 2x(-2) = 0 (d) N2O5: the oxidation state must be +5 because 2x(+5) + 5x(-2) = 0 (e) N2O4: the oxidation state must be +4 because 2x(+4) + 4x(-2) = 0

Name each compound using common naming conventions for nitrogen oxides

Now that we know the oxidation states of nitrogen in each compound, we can name them: (a) N2O: Dinitrogen monoxide (also known as nitrous oxide or "laughing gas") (b) NO: Nitrogen monoxide (also known as nitric oxide) (c) NO2: Nitrogen dioxide (d) N2O5: Dinitrogen pentoxide (e) N2O4: Dinitrogen tetroxide

Key concepts

Oxidation State

The concept of oxidation state is a key aspect in understanding nitrogen oxides. It represents the charge an atom would have if all bonds to atoms of different elements were completely ionic. For oxygen, the oxidation state is usually -2. By using this information, we can calculate the oxidation states of nitrogen in various compounds.

- For \( \text{N}_2\text{O} \): Oxygen is -2, so nitrogen in this compound must be +1 to balance the overall charge.- In \( \text{NO} \): With oxygen at -2, nitrogen is +2.- For \( \text{NO}_2 \): Nitrogen needs to be +4 to counteract the two oxygens.- In \( \text{N}_2\text{O}_5 \): Nitrogen is at +5, with five oxygens to balance.- Finally, \( \text{N}_2\text{O}_4 \) has nitrogen at +4 like \( \text{NO}_2 \).Understanding these states helps us grasp how nitrogen behaves in different compounds and prepares us to name them correctly.

Chemical Nomenclature

Learning the names of compounds based on their chemical composition is important, especially in chemistry.

For nitrogen oxides, we follow systematic naming conventions:

• For \( \text{N}_2\text{O} \), it's called dinitrogen monoxide, commonly known as nitrous oxide or laughing gas. The 'di' prefix indicates two nitrogen atoms.
• In \( \text{NO} \), it's simply nitrogen monoxide or nitric oxide, with no prefixes for single atoms.
• \( \text{NO}_2 \) is nitrogen dioxide, conveying two oxygen atoms.
• With \( \text{N}_2\text{O}_5 \), we get dinitrogen pentoxide, signifying five oxygens.
• Finally, \( \text{N}_2\text{O}_4 \) is dinitrogen tetroxide, marking four oxygens.

These naming rules help us communicate the structure of the compound clearly and efficiently.

Urban Air Pollution

Nitrogen oxides are significant contributors to urban air pollution. They primarily come from combustion engines and industrial processes. These compounds are not just harmful themselves but also play a role in forming other pollutants.

• \( \text{NO} \) and \( \text{NO}_2 \) are referred to collectively as NOx gases. They react with sunlight to create ground-level ozone, a key component of smog.
• These gases can irritate the respiratory system and exacerbate asthma.
• Environmental impacts include contributing to acid rain, which damages ecosystems and buildings.

Efforts to reduce nitrogen oxide emissions include stricter vehicle regulations and cleaner industrial practices. Understanding their role in pollution helps drive both policy and personal action to improve air quality.