Question

An acid such as \(\mathrm{HCl}\) that strongly conducts an electric current when dissolved in water is said to be a(n) acid.

Short answer

An acid such as HCl that strongly conducts an electric current when dissolved in water is said to be a(n) **strong acid**. This is because it dissociates completely in water, releasing a high concentration of hydrogen ions (H+) and allowing for efficient conductivity.

Step-by-step solution

Understand the properties of the acid

A strong acid is one that dissociates completely in water, releasing a high concentration of hydrogen ions (H+). In the case of hydrochloric acid (HCl), this dissociation occurs as follows: \[ \mathrm{HCl_{(aq)} \rightarrow H^+_{(aq)} + Cl^-_{(aq)}}\] This property of the acid allows it to conduct an electric current efficiently, as the charged ions can easily move and carry the charge.

Provide the term describing the acid

Now that we understand the properties of the acid, we can state that an acid such as HCl that strongly conducts an electric current when dissolved in water is said to be a(n) **strong acid**.

Key concepts

Acid Dissociation

Understanding the concept of acid dissociation is essential for grasping the nature of strong acids. Acids are substances that can donate hydrogen ions (H+), also known as protons, to the solution. The measure in which an acid releases these ions into water is called dissociation.

For instance, hydrochloric acid (\(\mathrm{HCl}\)), a classic example of a strong acid, dissociates completely when it is mixed with water. The reaction can be written as \[ \mathrm{HCl_{(aq)} \rightarrow H^+_{(aq)} + Cl^-_{(aq)}} \]. In this reaction, the subscript 'aq' stands for aqueous, indicating that the species are in a water-based solution.

The dissociation is crucial as it yields free moving ions in the solution, which directly relates to the electrical conductivity of the acid in water. A more complete dissociation indicates a stronger acid. Students should be aware that not all acids dissociate fully, and these are referred to as weak acids.

Electric Conductivity in Acids

The electric conductivity in acids is a fascinating area of chemistry that is closely tied to the dissociation of acids in solution. Conductivity is the measure of how well a substance can carry an electric current, and in the case of acids, it depends greatly on the presence of ions.

When an acid dissociates in water, it releases hydrogen ions (\(\mathrm{H^+}\)) and anions, in our case chloride ions (\(\mathrm{Cl^-}\)), which are charged particles. These ions are free to move in the solution and thus, can carry an electric current. The more ions an acid releases into the solution, the higher the conductivity. A strong acid, which dissociates completely, will typically have a higher electric conductivity than a weak acid that partially dissociates.

To measure the conductivity of an acid solution, one can use a conductivity meter that detects the movement of ions in the solution. This measurement can help to determine the strength of the acid and, practically, it has crucial applications in industries like battery development and water quality testing.

Hydrogen Ions

Hydrogen ions (\(\mathrm{H^+}\)) are central to the behavior of acids in water and their ability to exhibit properties such as conductivity. These positively charged ions are created when an acid dissociates in an aqueous solution.

The concentration of hydrogen ions in a solution is a definitive measure of the solution's acidity, with a higher concentration indicating a lower pH and a more acidic solution. The pH scale is, in fact, a logarithmic representation of the hydrogen ion concentration. The importance of these ions extends beyond their role in defining pH; they also participate in a variety of chemical reactions, including neutralization with bases to form water and salts.

In an educational context, it is crucial for students to understand that the presence of hydrogen ions is what gives acids their characteristic properties, and by controlling the concentration of these ions, one can manipulate the strength and reactivity of the acid. Experiments involving titration are often used to illustrate how the manipulation of hydrogen ions can affect the outcome of chemical reactions.