Question

In addition to the three strong acids emphasized in the chapter $(\mathrm{HCl},{\mathrm{HNO}}_3,\text{ and }{\mathrm{H}}_2{\mathrm{SO}}_4),$ hydrobromic acid, HBr, and perchloric acid, ${\mathrm{HClO}}_4$, are strong acids. Write equations for the dissociation of each of these additional strong acids in water.

Short answer

The dissociation equations for Hydrobromic acid (HBr) and Perchloric acid (HClO4) in water are as follows: 1. Hydrobromic acid (HBr): $$\mathrm{HBr}(\mathrm{aq})\to {\mathrm{H}}^{+}(\mathrm{aq})+{\mathrm{Br}}^{-}(\mathrm{aq})$$ 2. Perchloric acid (HClO4): $${\mathrm{HClO}}_4(\mathrm{aq})\to {\mathrm{H}}^{+}(\mathrm{aq})+{\mathrm{ClO}}_4^{-}(\mathrm{aq})$$

Step-by-step solution

Dissociation of Hydrobromic acid (HBr) in water

When HBr dissociates in water, it breaks down into a hydrogen ion (H+) and a bromide ion (Br-). The equation that describes this process is: $$\mathrm{HBr}(\mathrm{aq})\to {\mathrm{H}}^{+}(\mathrm{aq})+{\mathrm{Br}}^{-}(\mathrm{aq})$$

Dissociation of Perchloric acid (HClO4) in water

When HClO4 dissociates in water, it breaks down into a hydrogen ion (H+) and a perchlorate ion (ClO4-). The equation that describes this process is: $${\mathrm{HClO}}_4(\mathrm{aq})\to {\mathrm{H}}^{+}(\mathrm{aq})+{\mathrm{ClO}}_4^{-}(\mathrm{aq})$$ These are the dissociation equations for Hydrobromic acid (HBr) and Perchloric acid (HClO4) in water.

Key concepts

Acid Dissociation

Acid dissociation is a fundamental concept in chemistry, especially when dealing with strong acids. It involves the process in which an acid breaks down into its constituents, typically releasing hydrogen ions (H${}^{+}$) into an aqueous solution. This process is crucial because the release of hydrogen ions is what gives acids their characteristic properties.
When a strong acid dissociates, it does so completely. This means it fully separates into ions, unlike weak acids that only partially dissociate.
This complete dissociation is represented in chemical equations by the single arrow (→), indicating the reaction goes to completion.In solution, strong acids contribute to a high concentration of H${}^{+}$ ions. These ions are responsible for lowering the pH of the solution, making the environment more acidic.

• The degree of dissociation is so high that the acid essentially contributes all its available hydrogen.
• Each strong acid has unique dissociation products depending on its molecular composition.

For example, when hydrobromic acid dissociates, it produces bromide ions, while when perchloric acid dissociates, it yields perchlorate ions.

Hydrobromic Acid

Hydrobromic acid (HBr) is one of the strong acids discussed in chemistry. It is known for its complete dissociation in water, similar to hydrochloric acid (HCl).
HBr's ability to fully dissociate makes it an effective proton donor in aqueous solutions.When hydrobromic acid is placed in water, it separates fully into hydrogen ions (H${}^{+}$) and bromide ions (Br${}^{-}$). The dissociation equation is given by:$$\mathrm{HBr}(\mathrm{aq})\to {\mathrm{H}}^{+}(\mathrm{aq})+{\mathrm{Br}}^{-}(\mathrm{aq})$$This equation captures the essence of HBr as a strong acid, revealing how it contributes to the high acidity of a solution by increasing its H${}^{+}$ ion concentration.

• Hydrobromic acid is used in various industrial processes, including as a reagent in chemical synthesis.
• Its complete dissociation makes it highly effective in reactions requiring a strong acid.

If you see HBr in a chemical equation, you can confidently assume complete dissociation, allowing you to predict the reaction outcome more accurately.

Perchloric Acid

Perchloric acid (HClO${}_4$) is another example of a strong acid known for its complete dissociation in water. It is, in fact, one of the strongest acids available, often used in laboratories and industrial applications.
The structure of perchloric acid includes a chlorine atom centrally bonded to four oxygen atoms, forming the perchlorate ion (ClO${}_4^{\text{-}}$) upon dissociation.When perchloric acid is dissolved in water, it completely separates into hydrogen ions (H${}^{+}$) and perchlorate ions. This can be expressed with the dissociation equation:$${\mathrm{HClO}}_4(\mathrm{aq})\to {\mathrm{H}}^{+}(\mathrm{aq})+{\mathrm{ClO}}_4^{-}(\mathrm{aq})$$This dissociation significantly increases the concentration of H${}^{+}$ ions in solution, contributing to a highly acidic environment.

• Perchloric acid is utilized in analytical chemistry due to its strong oxidizing properties.
• Its complete dissociation is leveraged in titration and etching processes.

Due to its extreme reactivity, it must be handled with care, adhering to safety protocols to prevent hazards.