Problem 141 - Introductory Chemistry Atoms First

Question

Many acids can be thought of as anions that have an \(\mathrm{H}^{+}\) ion attached to them. Fill in the following table: \begin{tabular}{|l|l|l|l|} \hline Anion & Anion name & Acid formula & Acid name \\ \hline \(\mathrm{F}^{-}\) & & & \\ \hline \(\mathrm{NO}_{3}^{-}\) & & & \\ \hline \(\mathrm{Cl}^{-}\) & & & \\ \hline \(\mathrm{C}_{2} \mathrm{H}_{3} \mathrm{O}_{2}^{-}\) & & & \\ \hline \(\mathrm{NO}_{2}^{-}\) & & & \\ \hline \end{tabular}

Step-by-Step Solution

Answer

Here is the completed table with the anion names, acid formulas, and acid names: \begin{tabular}{|l|l|l|l|} \hline Anion & Anion name & Acid formula & Acid name \\ \hline $\mathrm{F}^{-}$ & Fluoride & HF & Hydrofluoric Acid \\ \hline $\mathrm{NO}_{3}^{-}$ & Nitrate & HNO3 & Nitric Acid \\ \hline $\mathrm{Cl}^{-}$ & Chloride & HCl & Hydrochloric Acid \\ \hline $\mathrm{C}_{2}\mathrm{H}_{3}\mathrm{O}_{2}^{-}$ & Acetate & HC2H3O2 & Acetic Acid \\ \hline $\mathrm{NO}_{2}^{-}$ & Nitrite & HNO2 & Nitrous Acid \\ \hline \end{tabular}

Step 1: Identify the anion names

First, we will determine the names of the given anions: 1. F- : Fluoride 2. NO3- : Nitrate 3. Cl- : Chloride 4. C2H3O2- : Acetate 5. NO2- : Nitrite

Step 2: Determine the acid formulas

To obtain the acid formula, we will add an H+ ion to each anion. The formulas for the acids are: 1. HF (F- + H+) 2. HNO3 (NO3- + H+) 3. HCl (Cl- + H+) 4. HC2H3O2 (C2H3O2- + H+) 5. HNO2 (NO2- + H+)

Step 3: Identify the acid names

Now, we will name each of the acids based on their formulas: 1. HF: Hydrofluoric Acid 2. HNO3: Nitric Acid 3. HCl: Hydrochloric Acid 4. HC2H3O2: Acetic Acid 5. HNO2: Nitrous Acid With this information, we can now fill in the table: \begin{tabular}{|l|l|l|l|} \hline Anion & Anion name & Acid formula & Acid name \\ \hline F- & Fluoride & HF & Hydrofluoric Acid \\ \hline NO3- & Nitrate & HNO3 & Nitric Acid \\ \hline Cl- & Chloride & HCl & Hydrochloric Acid \\ \hline C2H3O2- & Acetate & HC2H3O2 & Acetic Acid \\ \hline NO2- & Nitrite & HNO2 & Nitrous Acid \\ \hline \end{tabular}

Key Concepts

Anion Names

Anions are negatively charged ions. They are formed when an atom gains one or more electrons. Each anion has a distinct name. It often reflects the element from which it originates or the compound form it is part of. Understanding anion names is crucial in chemistry as they form the foundation for naming their corresponding acids. Some common rules include:

• Non-metal elements typically end with "-ide." For example, chlorine becomes "chloride" as an anion.
• Oxyanions (ions that contain oxygen) may end with "-ate" or "-ite." For example, nitrate ( O_3^- ) and nitrite ( O_2^- ).

This naming convention helps in identifying and categorizing the anions, which is pivotal when discussing their respective acids.

Acid Formulas

Acid formulas are derived by adding an H^+ ion to the anion. This combination of hydrogen ions with anions results in a neutral compound—an acid. Identifying acid formulas involves understanding the basic charges:

• Each H^+ neutralizes one negative charge of the anion. For example, the fluoride ion ( F^- ) becomes the hydrofluoric acid ( HF ).
• The resulting formula reflects the composition of the acid. For instance, anion NO_3^- results in nitric acid ( HNO_3 ) by adding H^+ to balance the negative charge.

This step is a vital bridge in connecting anions to their resulting acids.

Naming Acids

Acid names are based on the names of the anion they contain. The pattern of naming acids helps in predicting their properties and their behavior in reactions:

• If the anion ends with "-ide," the acid name begins with "hydro-" and ends with "-ic acid." For example, chloride ( Cl^- ) forms hydrochloric acid ( HCl ).
• For anions ending in "-ate," the corresponding acids are named with "-ic acid." For example, nitrate ( NO_3^- ) becomes nitric acid ( HNO_3 ).
• Anions with "-ite" endings form acids named with "-ous acid." Thus, nitrite ( NO_2^- ) becomes nitrous acid ( HNO_2 ).

Mastering these naming rules allows one to quickly communicate the acid's identity and its properties.

Chemistry Table Completion

Completing a chemistry table involves matching each anion with its name, deriving the acid formula, and naming the acid. In this exercise, you filled in the table as follows:

• For fluoride ( F^- ), the acid formula is HF , resulting in hydrofluoric acid.
• Nitrate ( NO_3^- ) converts to HNO_3 , known as nitric acid.
• Chloride ( Cl^- ) becomes HCl , producing hydrochloric acid.
• Acetate ( C_2H_3O_2^- ) forms HC_2H_3O_2 , yielding acetic acid.
• Nitrite ( NO_2^- ) derives HNO_2 , known as nitrous acid.

This process showcases an important skill in chemistry: systematically translating between chemical symbols and language to represent molecular structures accurately. It helps students understand how chemical processes are documented and communicated in a professional context.