Question

Assign the oxidation state for nitrogen in each of the following. a \(\mathrm{L}_{3} \mathrm{N} \quad\) d. NO \(\quad\) g. \(\mathrm{NO}_{2}^{-}\) b. \(\mathrm{NH}_{3} \quad\) e. \(\mathrm{N}_{2} \mathrm{O} \quad\) h. \(\mathrm{NO}_{3}^{-}\) c\(\mathrm{N}_{2} \mathrm{H}_{4} \quad\) f. \(\mathrm{NO}_{2} \quad\) i. \(\mathrm{N}_{2}\)

Short answer

The oxidation states of nitrogen in the given compounds are: a. Li3N: -3 b. NH3: -3 c. N2H4: -2 d. NO: +2 e. N2O: +1 f. NO2: +4 g. NO2-: +3 h. NO3-: +5 i. N2: 0

Step-by-step solution

Recall the rules for assigning oxidation states

In order to determine the oxidation states for nitrogen in each of the given compounds, we need to keep certain rules in mind: 1. The oxidation state of an element in its free elemental form is 0. 2. The oxidation state of a monoatomic Ion is equal to the charge it carries. 3. In a neutral compound, the sum of oxidation states is 0; in a polyatomic ion, the sum is equal to the charge of the ion. 4. The more electronegative element carries the negative oxidation state, and the less electronegative element carries the positive one.

Determine the oxidation states of nitrogen

a. Li3N - Lithium nitride Let's determine the oxidation state for N in Li3N. Li: +1 (alkali metals have +1 oxidation state) For three lithium atoms, the total charge is +3. To maintain neutrality in the compound, the nitrogen atom must carry a -3 charge. Oxidation state of N: -3 b. NH3 - Ammonia Let's determine the oxidation state for N in NH3. H: +1 For three hydrogen atoms, the total charge is +3. To maintain neutrality in the compound, the nitrogen atom must carry a -3 charge. Oxidation state of N: -3 c. N2H4 - Hydrazine Let's determine the oxidation state for N in N2H4. H: +1 For four hydrogen atoms, the total charge is +4. In order to maintain neutrality, the sum of the oxidation states of the two nitrogen atoms must be -4. Therefore, each nitrogen atom must carry an oxidation state of -2. Oxidation state of N: -2 d. NO - Nitrogen monoxide Let's determine the oxidation state for N in NO. O: -2 To maintain neutrality in the compound, the nitrogen atom must carry a +2 charge. Oxidation state of N: +2 e. N2O - Nitrous oxide Let's determine the oxidation state for N in N2O. O: -2 In order to maintain neutrality, the sum of the oxidation states of the two nitrogen atoms must be +2. Therefore, each nitrogen atom must carry an oxidation state of +1. Oxidation state of N: +1 f. NO2 - Nitrogen dioxide Let's determine the oxidation state for N in NO2. O: -2 For two oxygen atoms, the total charge is -4. To maintain neutrality in the compound, the nitrogen atom must carry a +4 charge. Oxidation state of N: +4 g. NO2- - Nitrite ion Let's determine the oxidation state for N in NO2-. O: -2 For two oxygen atoms, the total charge is -4. Since the charge of the ion is -1, the nitrogen atom must carry an oxidation state of +3. Oxidation state of N: +3 h. NO3- - Nitrate ion Let's determine the oxidation state for N in NO3-. O: -2 For three oxygen atoms, the total charge is -6. Since the charge of the ion is -1, the nitrogen atom must carry an oxidation state of +5. Oxidation state of N: +5 i. N2 - Nitrogen molecule Let's determine the oxidation state for N in N2. As N2 is an elemental form of nitrogen, the oxidation state for nitrogen is 0. Oxidation state of N: 0

Key concepts

Nitrogen Compounds

Nitrogen compounds come in various forms and are a fundamental part of chemistry. These compounds are composed of nitrogen atoms, often combined with other elements like hydrogen, oxygen, or metals. Understanding nitrogen compounds begins with recognizing their diverse chemical structures and behaviors.

Some common nitrogen compounds include:

• Ammonia (NH₃),
• Nitrogen dioxide (NO₂), and
• Nitrite (NO₂⁻) and Nitrate ions (NO₃⁻).

Each of these compounds behaves differently due to the unique bonding and electron arrangements of nitrogen. Studying these differences helps predict the compound's reactivity and role in larger chemical reactions. For example, ammonia is a base, often seen in fertilizers, whereas nitrogen dioxide is an air pollutant with entirely different chemical properties.

Learning about nitrogen compounds is crucial because they are involved in major chemical processes like protein synthesis and environmental phenomena such as the nitrogen cycle.

Oxidation State Rules

Oxidation states, or oxidation numbers, are important for understanding how electrons are distributed in a chemical compound. These numbers help track electron transfer during chemical reactions, especially redox reactions. For nitrogen compounds, identifying the oxidation state of nitrogen helps to predict how the compound behaves chemically.

Key rules for determining oxidation states include:

• The oxidation state of an atom in its elemental form is always 0. For example, in N₂, each nitrogen atom has an oxidation state of 0.


• For monoatomic ions, the oxidation state equals the ion's charge.


• In molecules, more electronegative elements receive closer-to-zero oxidation states while others are assigned more positive values.

Understanding these rules allows chemists to determine the charge balance within a compound and predict its ability to participate in redox reactions. When applying these rules to nitrogenous compounds, focus on the number of nitrogen atoms and their bonding partners.

Chemical Compounds

Chemical compounds consist of two or more elements chemically bonded together. They can be categorized into ionic and covalent compounds. In nitrogen compounds, bonds with other elements such as hydrogen and oxygen can form stable structures.

Nitrogen often forms covalent bonds because it needs to share electrons with other elements to achieve a stable electronic configuration. For instance, in ammonia (NH₃), nitrogen shares electrons with hydrogen atoms to complete its octet.

Key aspects of chemical compounds include:

• Structure: The arrangement of atoms dictates the physical and chemical properties.
• Stability: A compound's bonding pattern can indicate how stable it is and predict its reactivity.
• Reactivity: Some compounds react more easily than others, impacting their applications and handling.

A broad knowledge of chemical compounds allows students to grasp the complexity of chemical reactions and the stability of compounds, aiding in fields like pharmacology and materials science.

Redox Chemistry

Redox chemistry, or reduction-oxidation reactions, focuses on the transfer of electrons between atoms. In these reactions, one species is oxidized (loses electrons) and another is reduced (gains electrons). Understanding redox reactions is crucial in studying nitrogen compounds since many undergo changes in their oxidation states during reactions.

For example, in the reaction of nitric oxide (NO) to form nitrate (NO₃⁻), nitrogen undergoes oxidation. Tracking the change in oxidation states helps determine how electrons are transferred throughout the reaction.

Key elements of redox chemistry include:

• Oxidizing agents: Substances that gain electrons and are reduced in the reaction.
• Reducing agents: Substances that lose electrons and are oxidized in the reaction.
• Electron flow: Essential for energy conversion processes, such as in batteries and biological respiration.

By mastering redox chemistry concepts, students can better understand not only nitrogen compounds but a variety of chemical reactions involving electron transfer. This knowledge is pivotal in both industrial applications and biological systems, like cellular respiration.