Problem 20 - Chemistry Matter and Change

Question

Name the following acids. Assume each compound is dissolved in water. $$\mathrm{HClO}_{3}$$

Step-by-Step Solution

Answer

The acid name is chloric acid.

Step 1: Understand the Acid Naming Rules

When naming acids, if the anion does not contain oxygen, the acid name usually begins with 'hydro-' and ends with '-ic.' However, for oxyacids (acids that contain oxygen), the naming is different. If the anion name ends in '-ate,' the acid name is formed with the suffix '-ic.' If the anion ends in '-ite,' the acid name is formed with '-ous.'

Step 2: Identify the Anion in the Compound

The chemical formula given is \( \mathrm{HClO}_{3} \). To name this acid, first, identify the anion, which is the part of the formula that follows hydrogen. In this case, the anion is \( \mathrm{ClO}_{3}^{-} \), which is called chlorate.

Step 3: Apply the Naming Rule for Oxyacids

Since the anion is chlorate (\( \mathrm{ClO}_{3}^{-} \)), which ends in '-ate,' we apply the oxyacid naming rule. Replace the '-ate' suffix of the anion with '-ic' to form the acid name. Therefore, chlorate becomes chloric, resulting in the name 'chloric acid.'

Key Concepts

Oxyacids

Oxyacids are a type of acid that contains oxygen. These acids are quite common and play important roles in chemistry because they help us understand how acids are named and categorized. The key feature of an oxyacid is its polyatomic ion which contains oxygen along with another element.
In the naming of oxyacids, it's crucial to note how the suffix of the anion changes the name of the acid.

• If the anion ends in '-ate', the acid will take the suffix '-ic'. For example, nitrate ( itrate) becomes nitric acid ( HNO_3 t).
• If the anion ends in '-ite', the acid name uses the suffix '-ous'. For instance, sulfite ( SO_3^{2-} t) turns into sulfurous acid ( H_2SO_3 t).

I'll guide you through each process step-by-step for clarity.

Anion Identification

An important step in naming acids is identifying the anion. An anion is the negatively charged portion of the chemical compound. To identify the anion in an acid's formula, you need to look at the part that follows hydrogen (H).
In a compound like HClO_3 , the anion is ClO_3^{-} . This is known as the chlorate ion.

• The chlorate ion consists of chlorine and oxygen atoms.
• The charge is indicated by the "-" sign, meaning it has gained electrons.

Recognizing this negative ion is key because it determines the acid's name.

Chemical Formula Interpretation

Interpreting chemical formulas helps in understanding what each element and number signify in a compound. Let's break down HClO_3 as an example:

• 'H' represents a hydrogen atom. It often indicates the presence of an acid when seen at the start of a formula.
• 'Cl' stands for chlorine, a nonmetal that combines with oxygen in this compound.
• 'O3' refers to three oxygen atoms. Together with chlorine, they form the chlorate ion.

The formula tells us about the compound's composition, highlighting its constituent elements and their quantity. Such interpretations are critical in correctly naming acids and predicting their chemical behavior.

Chlorate Anion

The chlorate anion ( ClO_3^{-} ) is a specific type of polyatomic ion, which means it consists of more than one atom. Here, it includes one chlorine atom and three oxygen atoms.
This anion is quite significant in chemistry due to its presence in various compounds and its role in acid naming.

• The chlorate ion ends with the suffix '-ate', which leads to the acid being named with the suffix '-ic'. This explains why chlorate turns into chloric acid.
• Understanding its structure and naming rules helps demystify acid naming conventions and strengthens the foundational knowledge of chemistry.

Knowing how to deal with chlorate is fundamental when practicing chemical nomenclature.