Question

Suggest a list of the substances where carbon can exhibit oxidation states from \(-4\) to \(+4\) and nitrogen from \(-3\) to \(+5\).

Short answer

Carbon: CH_4, CO, CCl_4, CO_2; Nitrogen: NH_3, N_2, NO, NO_2, NO_3^-.

Step-by-step solution

Understanding Carbon Oxidation States

Identify where carbon exhibits its lowest oxidation state (-4). In methane ( CH_4), carbon is in this oxidation state. Similarly, carbon exhibits a +4 oxidation state in carbon dioxide ( CO_2). Therefore, carbon oxidation states from -4 to +4 include compounds like CH_4, carbon monoxide ( CO), carbon tetrachloride ( CCl_4), and CO_2.

Understanding Nitrogen Oxidation States

Identify compounds where nitrogen shows various oxidation states. From nitride ion ( N^{3-}) at -3 oxidation state to nitrates ( NO_3^-), nitrogen spans states from -3 to +5. Other examples include ammonia ( NH_3) at -3, nitrogen gas ( N_2) at 0, nitric oxide ( NO) at +2, and nitrogen dioxide ( NO_2) at +4.

Compiling the List

Compile a list of substances combining the knowledge of oxidation states for carbon and nitrogen. For carbon: CH_4 ( -4), carbon monoxide ( CO) ( +2), carbon tetrachloride ( CCl_4) ( +4), and CO_2 ( +4). For nitrogen: NH_3 ( -3), N_2 (0), NO ( +2), NO_2 ( +4), and NO_3^- ( +5).

Key concepts

Carbon Oxidation States

Carbon is an incredibly versatile element known for forming a variety of chemical compounds. Its oxidation state can range from -4 to +4, making it an excellent example for demonstrating the concept of oxidation states in chemistry. The oxidation state is essentially a measure of the degree of oxidation of an atom in a molecule. It indicates the number of electrons lost, gained, or shared as a result of chemical bonding.

One classic example of carbon in its lowest oxidation state, -4, is methane ( CH_4). In CH_4, carbon is bonded to four hydrogen atoms, each contributing one electron, thereby allowing carbon to achieve a state of stability with a complete octet.

• In carbon monoxide ( CO), carbon's oxidation state is +2, as it shares bonds with oxygen.
• In carbon tetrachloride ( CCl_4), carbon has an oxidation state of +4 through strong carbon-chlorine bonds.
• Finally, in carbon dioxide ( CO_2), carbon also exhibits an oxidation state of +4, with two double bonds to oxygen.

Understanding these states helps in studying various carbon-bearing compounds and predicting their chemical behaviors.

Nitrogen Oxidation States

Nitrogen, much like carbon, can also show a variety of oxidation states, making it a key player in forming numerous chemical compounds. The range of nitrogen's oxidation states extends from -3 to +5. This wide range reflects nitrogen's ability to form bonds by donating, accepting, or sharing electrons.

At -3 oxidation state, we observe nitrogen in the form of the nitride ion ( N^{3-}) in some metal nitrides, where it has gained electrons. Ammonia ( NH_3) also contains nitrogen in a -3 oxidation state, where nitrogen forms three bonds with hydrogen.

• Nitrogen gas ( N_2), displaying an oxidation state of 0, is what we breathe—a stable molecule due to a triple bond between two nitrogen atoms.
• Nitric oxide ( NO) has a nitrogen oxidation state of +2, involved in reactions within our bodies.
• Nitrogen dioxide ( NO_2) shows an oxidation state of +4, reflecting additional bonding with oxygen.
• Finally, nitrates ( NO_3^-) feature nitrogen in a +5 oxidation state, commonly found in fertilizers and crucial for plant growth.

These examples highlight nitrogen’s flexibility and its central role in diverse chemical reactions.

Chemical Compounds

Chemical compounds are substances formed from two or more elements, where the atoms are bonded together in fixed proportions. They are central to understanding oxidation states because the oxidation state of an element within a compound gives insight into the nature of its chemical bonds.

For example, in methane ( CH_4), the carbon atom, with an oxidation state of -4, forms simple, nonpolar covalent bonds with hydrogen. Meanwhile, carbon dioxide ( CO_2), where carbon has an oxidation state of +4, involves polar covalent bonds with oxygen, illustrating a shift in electron density.

• In ammonia ( NH_3), nitrogen forms polar covalent bonds with hydrogen when it holds a -3 oxidation state.
• Conversely, in a nitrate ion ( NO_3^-), nitrogen's +5 oxidation state correlates with multiple strong bonds with highly electronegative oxygen atoms.

Thus, oxidation states are practical tools for predicting and understanding the chemical and physical characteristics of compounds. Studying the oxidation states of individual elements within compounds helps us predict their reactivity and interactions in chemical processes.