Problem 52 - Chemistry and Chemical Reactivity

Question

Write an overall, balanced equation for the reaction of \(\mathrm{Na}_{2} \mathrm{SO}_{3}\) with \(\mathrm{CH}_{3} \mathrm{CO}_{2} \mathrm{H},\) and name the reactants and products.

Step-by-Step Solution

Answer

The balanced equation is: \(\mathrm{Na}_2\mathrm{SO}_3 + 2\mathrm{CH}_3\mathrm{CO}_2\mathrm{H} \rightarrow 2\mathrm{CH}_3\mathrm{CO}_2\mathrm{Na} + \mathrm{SO}_2 + \mathrm{H}_2\mathrm{O}\). Reactants are sodium sulfite and acetic acid; products are sodium acetate, sulfur dioxide, and water.

Step 1: Identify the Reactants

The reactants for this chemical reaction are sodium sulfite \(\mathrm{Na}_2\mathrm{SO}_3\) and acetic acid \(\mathrm{CH}_3\mathrm{CO}_2\mathrm{H}\). We will be using these to determine the products of the reaction.

Step 2: Determine the Reaction Type

The reaction between \(\mathrm{Na}_2\mathrm{SO}_3\) and \(\mathrm{CH}_3\mathrm{CO}_2\mathrm{H}\) is typically a double displacement reaction, where the components switch partners, leading to the formation of new compounds.

Step 3: Identify the Products

In this reaction, the sulfate group \(\mathrm{SO}_3^{2-}\) from sodium sulfite will combine with the proton \(\mathrm{H}^+\) from acetic acid to form sulfur dioxide \(\mathrm{SO}_2\) and water \(\mathrm{H}_2\mathrm{O}\). Meanwhile, the sodium ion \(\mathrm{Na}^+\) will pair with the acetate ion \(\mathrm{CH}_3\mathrm{CO}_2^-\) to form sodium acetate \(\mathrm{CH}_3\mathrm{CO}_2\mathrm{Na}\).

Step 4: Write the Unbalanced Chemical Equation

We can write the unbalanced chemical equation based on the identified products: \[\mathrm{Na}_2\mathrm{SO}_3 + \mathrm{CH}_3\mathrm{CO}_2\mathrm{H} \rightarrow \mathrm{CH}_3\mathrm{CO}_2\mathrm{Na} + \mathrm{SO}_2 + \mathrm{H}_2\mathrm{O}\]

Step 5: Balance the Chemical Equation

To ensure the equation is balanced, we need to have the same number of each type of atom on both sides of the reaction. The balanced equation is: \[\mathrm{Na}_2\mathrm{SO}_3 + 2\mathrm{CH}_3\mathrm{CO}_2\mathrm{H} \rightarrow 2\mathrm{CH}_3\mathrm{CO}_2\mathrm{Na} + \mathrm{SO}_2 + \mathrm{H}_2\mathrm{O}\] This indicates that two acetic acid molecules are required for each sodium sulfite molecule to react completely.

Step 6: Name the Reactants and Products

The reactants are sodium sulfite (\(\mathrm{Na}_2\mathrm{SO}_3\)) and acetic acid (\(\mathrm{CH}_3\mathrm{CO}_2\mathrm{H}\)). The products after the reaction are sodium acetate (\(\mathrm{CH}_3\mathrm{CO}_2\mathrm{Na}\)), sulfur dioxide (\(\mathrm{SO}_2\)), and water (\(\mathrm{H}_2\mathrm{O}\)).

Key Concepts

Sodium Sulfite

Sodium sulfite, represented by the chemical formula \(\mathrm{Na}_2\mathrm{SO}_3\), is an important compound in chemistry, generally known for its ability to act as a reducing agent.

• Sodium sulfite is composed of sodium (Na) cations and sulfite (\(\mathrm{SO}_3^{2-}\)) anions.
• Its primary use is in the paper and pulp industry for the purposes of preserving and bleaching materials.
• In aqueous solutions, it tends to produce sulfur dioxide (\(\mathrm{SO}_2\)) when it reacts with acids due to the release of the sulfite ion.

When sodium sulfite is used in chemical reactions, it often combines with hydrogen ions from various acids, like acetic acid, to release sulfur dioxide and water. Understanding this behavior is key to predicting the outcomes of reactions it participates in.

Acetic Acid

Acetic acid, known chemically as \(\mathrm{CH}_3\mathrm{CO}_2\mathrm{H}\), is a fundamental organic compound found in vinegar.

• It has a distinct sour taste and pungent smell and is used in a variety of chemical processes as a reactant.
• This molecule is characterized by its carboxyl group (\(-\mathrm{COOH}\)), which is responsible for its acidic properties.
• Acetic acid is a weak acid, meaning it does not fully dissociate in water, yet it can easily donate protons (H\(^+\)) to react with other ions.

In the context of the reaction with sodium sulfite, acetic acid donates protons which trigger the formation of sulfur dioxide and water. Acetic acid’s ability to donate protons makes it a reactive participant in double displacement reactions, such as the one described here.

Double Displacement Reaction

Double displacement reactions are a type of chemical reaction where components of the reacting compounds switch places, resulting in the formation of new compounds.

• These reactions generally occur when two ionic compounds react in an aqueous solution, leading to the exchange of ions.
• The typical outcome of this exchange involves the formation of a precipitate, gas, or water, indicating a chemical transformation.
• In double displacement reactions like the one between sodium sulfite and acetic acid, the ions effectively "swap partners." This results in a new combination of ions forming different products.

In the reaction under consideration, sodium sulfite provides the sulfite ion, while acetic acid offers hydrogen ions, leading to the formation of sodium acetate, sulfur dioxide gas, and water. The driving factor behind such reactions is often the formation of a gas, a new ionic compound, or water, signaling a successful chemical transformation.