Question

Write the conjugate base for each of the following acids: a. \(\mathrm{H}_{2} \mathrm{S}\) b. \(\mathrm{HS}^{-}\) c. \(\mathrm{NH}_{3}\) d. \(\mathrm{H}_{2} \mathrm{SO}_{3}\)

Short answer

The conjugate bases for the given acids are: a. $\mathrm{H}_{2} \mathrm{S}$: $\mathrm{HS}^{-}$ b. $\mathrm{HS}^{-}$: $\mathrm{S}^{2-}$ c. $\mathrm{NH}_{3}$: $\mathrm{NH}_{2}^{-}$ d. $\mathrm{H}_{2} \mathrm{SO}_{3}$: $\mathrm{HSO}_{3}^{-}$

Step-by-step solution

Identify the Acid

The given acid is \(\mathrm{H}_{2} \mathrm{S}\).

Remove One Proton

Removing one proton (H+) from the acid \(\mathrm{H}_{2} \mathrm{S}\) gives the conjugate base, so \(\mathrm{H}_{2} \mathrm{S} - \mathrm{H}^{+}\).

Write the Formula for the Conjugate Base

The conjugate base for \(\mathrm{H}_{2} \mathrm{S}\) is \(\mathrm{HS}^{-}\). b. HS^-

Identify the Acid

The given acid is \(\mathrm{HS}^{-}\).

Remove One Proton

Removing one proton (H+) from the acid \(\mathrm{HS}^{-}\) gives the conjugate base, so \(\mathrm{HS}^{-} - \mathrm{H}^{+}\).

Write the Formula for the Conjugate Base

The conjugate base for \(\mathrm{HS}^{-}\) is \(\mathrm{S}^{2-}\). c. NH3

Identify the Acid

The given acid is \(\mathrm{NH}_{3}\).

Remove One Proton

Removing one proton (H+) from the acid \(\mathrm{NH}_{3}\) gives the conjugate base, so \(\mathrm{NH}_{3} - \mathrm{H}^{+}\).

Write the Formula for the Conjugate Base

The conjugate base for \(\mathrm{NH}_{3}\) is \(\mathrm{NH}_{2}^{-}\). d. H2SO3

Identify the Acid

The given acid is \(\mathrm{H}_{2} \mathrm{SO}_{3}\).

Remove One Proton

Removing one proton (H+) from the acid \(\mathrm{H}_{2} \mathrm{SO}_{3}\) gives the conjugate base, so \(\mathrm{H}_{2} \mathrm{SO}_{3} - \mathrm{H}^{+}\).

Write the Formula for the Conjugate Base

The conjugate base for \(\mathrm{H}_{2} \mathrm{SO}_{3}\) is \(\mathrm{HSO}_{3}^{-}\).

Key concepts

Conjugate Base

In acid-base chemistry, a conjugate base is the species that remains after an acid has donated a proton (H+). When an acid loses its proton, it transforms into its conjugate base. This transformation is an essential part of understanding how acids and bases interact.
For example, in the reaction where \(H_2S\) loses a proton, the result is the conjugate base \(HS^-\). This pattern of removing hydrogen ions from a substance helps us identify conjugate base molecules.
Each acid has a unique conjugate base, and this pair (acid and conjugate base) is linked by the removal of a proton. Recognizing these pairs helps in predicting and understanding the products of acid-base reactions.

Proton Removal

Proton removal, also known as deprotonation, is the process where a proton (H+) is taken away from a molecule. This is a key step in many chemical reactions, especially those involving acids and bases.
When a proton is removed, the chemical structure of the molecule changes. For an acid, losing a proton results in its conjugate base.
In the given acids, removing one proton from \(H_2S\) results in \(HS^-\), while for \(NH_3\), removing a proton gives \(NH_2^-\).
Understanding proton removal helps in grasping how chemical reactivity changes and how new molecules form through simple transformations.

Acidic Reactions

Acidic reactions involve the transfer of protons between substances. When an acid reacts, it donates a proton to another molecule, a base. This process rearranges the atoms within the reaction, leading to new products.
Acid-base reactions are important in numerous chemical applications, from laboratory syntheses to biological processes.
For instance, the reaction of \(H_2SO_3\) that forms \(HSO_3^-\) shows how acids can transform during transfer processes. These reactions maintain balance by creating conjugate pairs that differ simply by a hydrogen.
Observing acidic reactions and their resulting products is vital for understanding and predicting chemical behavior.

Chemical Formulas

Chemical formulas are representations of molecules showing the elements involved and their proportions. They provide crucial insight into the composition and structure of a molecule.
In acids and bases, these formulas often include hydrogen atoms that can be transferred or removed during reactions.
A formula such as \(H_2SO_3\) indicates two hydrogen atoms, one sulfur atom, and three oxygen atoms. When analyzing reactions, changing the chemical formula by removing a proton results in a different molecular structure, such as \(HSO_3^-\).
Accurately interpreting chemical formulas is fundamental for understanding molecular changes during reactions, making them a foundational tool in chemistry.