Question

Challenge The ionic compound \(\mathrm{NH}_{4} \mathrm{ClO}_{4}\) is a key reactant used in solid rocket boosters, such as those that power the Space Shuttle into orbit. Name this compound.

Short answer

The name of the ionic compound \(\mathrm{NH}_{4} \mathrm{ClO}_{4}\) is Ammonium Perchlorate.

Step-by-step solution

Identify Cation and Anion

The chemical formula of the given ionic compound is \(\mathrm{NH}_{4} \mathrm{ClO}_{4}\). We can identify that the cation is \(\mathrm{NH}_{4}^{+}\) (ammonium ion) and the anion is \(\mathrm{ClO}_{4}^{-}\) (perchlorate ion).

Name the cation and anion

Name the cation and anion according to their chemical symbols and charges: 1. \(\mathrm{NH}_{4}^{+}\): The cation is called ammonium (it's a polyatomic ion). 2. \(\mathrm{ClO}_{4}^{-}\): The anion is called perchlorate (it's also a polyatomic ion).

Combine the names of cation and anion

Now, we simply combine the names of the cation and anion, placing the cation name first and the anion name second: Ammonium Perchlorate Therefore, the name of the ionic compound \(\mathrm{NH}_{4} \mathrm{ClO}_{4}\) is Ammonium Perchlorate.

Key concepts

Cation and Anion Identification

When dealing with ionic compounds, it's essential to determine which ions are participating in the formation of the compound. Ions are atoms or groups of atoms that have an electrical charge due to the loss or gain of electrons. Cations carry a positive charge, and anions carry a negative charge. A simple way to identify them is to remember that 'cation' has a 't', thinking of it as a '+', while 'anion' has an 'n', resembling a '-'.

In our example, \( \mathrm{NH}_{4} \mathrm{ClO}_{4} \) can be broken down into its cation and anion. The ammonium ion, \( \mathrm{NH}_{4}^{+} \), is our cation with a positive charge, and the perchlorate ion, \( \mathrm{ClO}_{4}^{-} \), is our anion with a negative charge.

• Cations are usually metal ions or the ammonium ion in this case.
• Anions are often non-metal ions, such as halides or polyatomic ions like perchlorate.

While some compounds are binary, consisting of only a metal and a non-metal, many ionic compounds involve polyatomic ions, which brings us to our next concept.

Polyatomic Ions

Polyatomic ions are charged species composed of two or more atoms covalently bonded or of a metal complex that can be considered to be acting as a single unit. The charge on a polyatomic ion is the result of the difference between the number of protons and electrons. While the ammonium ion (\( \mathrm{NH}_{4}^{+} \) ) and the perchlorate ion (\( \mathrm{ClO}_{4}^{-} \) ) in our exercise are perfect examples, there are many others like the hydroxide \( \mathrm{OH}^{-} \) or the sulfate \( \mathrm{SO}_{4}^{2-} \).

Knowing your polyatomic ions is crucial as, unlike simple ions, they cannot be easily deduced from the name of the element and its charge. Thus, a solid grasp on common polyatomic ions is necessary for correct nomenclature. Here are some tips for learning them:

• Flashcards can be an effective memorization tool.
• Finding patterns in their names can help, like 'ate' and 'ite' endings, with 'ate' being the ion with more oxygen atoms.

Recognizing a polyatomic ion in a compound is key to naming it correctly, which leads us to our final step, 'chemical nomenclature'.

Chemical Nomenclature

The system of naming chemical compounds is known as chemical nomenclature. The purpose of this system is to give an unambiguous and systematic method of naming compounds to facilitate communication. For ionic compounds, the name is composed of the cation's name followed by the anion's name. If the cation is a metal ion with a fixed charge, its name is the same as the metal. If the metal can have more than one possible charge, like iron, it is indicated with Roman numerals in parentheses after the name of the metal.

For the compound \( \mathrm{NH}_{4} \mathrm{ClO}_{4} \), 'ammonium' is the name for the \( \mathrm{NH}_{4}^{+} \) ion, and 'perchlorate' is the name for \( \mathrm{ClO}_{4}^{-} \) ion. Thus, combining the names of the cation and anion yields 'Ammonium Perchlorate'. Key points to consider in naming:

• The cation gets named first followed by the anion.
• No prefixes are used to indicate the number of ions.
• For polyatomic ions, use their standard names without change.

Practicing chemical nomenclature using various examples will improve your skill and confidence in this all-important chemistry task.