Problem 45 - General Chemistry: Principles and Modern Applications

Question

Methane and sulfur vapor react to form carbon disulfide and hydrogen sulfide. Carbon disulfide reacts with \(\mathrm{Cl}_{2}(\mathrm{g})\) to form carbon tetrachloride and \(\mathrm{S}_{2} \mathrm{Cl}_{2}\) Further reaction of carbon disulfide and \(\overline{S_{2} C l_{2}}\) produces additional carbon tetrachloride and sulfur. Write a series of equations for the reactions described here.

Step-by-Step Solution

Answer

The balanced reactions are: \( CH4(g) + 2S(g) \rightarrow CS2(g) + 2H2S(g) \) , \( CS2(g) + 3Cl2(g) \rightarrow CCl4(g) +S2Cl2(g) \) , \( CS2(g) + S2Cl2(g) \rightarrow CCl4(g) + 2S(g) \)

Step 1: Formulate the first reaction

The first reaction is between Methane (CH4) and sulfur (S) to form Carbon disulfide (CS2) and Hydrogen Sulfide (H2S). This is represented by the equation: \(CH4(g) + 2S(g) \rightarrow CS2(g) + 2H2S(g) \)

Step 2: Formulate the second reaction

The second reaction is between Carbon disulfide (CS2) and Chlorine gas (Cl2) to form Carbon tetrachloride (CCl4) and Disulfur dichloride (S2Cl2). This is represented by the equation: \(CS2(g) + 3Cl2(g) \rightarrow CCl4(g) +S2Cl2(g) \)

Step 3: Formulate the third reaction

The third reaction is between Carbon disulfide (CS2) and Disulfur dichloride (S2Cl2) to form Carbon tetrachloride (CCl4) and sulfur (S). This is represented by the equation: \(CS2(g) + S2Cl2(g) \rightarrow CCl4(g) + 2S(g) \)

Key Concepts

Methane Reactions

Methane (\(\text{CH}_4\)) is a small molecule comprising one carbon atom bonded to four hydrogen atoms. It is the simplest alkane and an important component of the Earth's natural gas. Methane is highly flammable and is often used as a fuel source. However, it also reacts with other elements in a variety of chemical processes.

In the reactions outlined, methane reacts with sulfur vapor to produce carbon disulfide (\(\text{CS}_2\)) and hydrogen sulfide (\(\text{H}_2\text{S}\)). These are both sulfur compounds, which play crucial roles in industrial applications.

Here's a breakdown of what happens in this reaction:

• \(\text{CH}_4\), a single carbon tetrahedrally bonded to four hydrogens, engages with sulfur vapor.
• Two sulfur atoms (\(2 \text{S}\)) contribute to the formation of \(\text{CS}_2\), replacing the hydrogen atoms.
• As a by-product, \(\text{H}_2\text{S}\), a gas with a distinct rotten egg smell, is also formed.

Understanding these reactions provides insight into how simple molecules like methane can lead to the creation of more complex compounds. It also lays the foundation for exploring the transformations involving sulfur and various hydrocarbons.

Reaction Equations

Reaction equations are symbolic representations of chemical reactions. They show the starting substances (reactants) and the substances formed (products) as a result of the reaction. These equations are fundamental to understanding chemical processes.

The steps provided give us a clear, systematic approach to forming balanced reaction equations:

• The number of atoms for each element must be the same on both sides of the equation, adhering to the Law of Conservation of Mass.
• This is achieved by adjusting the coefficients before each molecular formula in the equation.
• Each reaction step in the sequence builds upon the previous ones, forming a logical chemical pathway.

This methodical balancing makes it easier to predict the outcomes of chemical reactions. For example, balancing methane’s and sulfur's conversion to \(\text{CS}_2\) and \(\text{H}_2\text{S}\) ensures all elements are accounted for, facilitating the understanding of the transformation process.

Sulfur Compounds

Sulfur is an abundant non-metal element that readily forms compounds with various other elements, including hydrogen and carbon. It is essential in the production of different materials and chemicals.

In the provided reactions, sulfur forms critical compounds such as hydrogen sulfide (\(\text{H}_2\text{S}\)), carbon disulfide (\(\text{CS}_2\)), and disulfur dichloride (\(\text{S}_2\text{Cl}_2\)). Each has unique properties and uses:

• \(\text{H}_2\text{S}\) is a toxic, colorless gas with a characteristic rotten-egg odor, used in industrial processes.
• \(\text{CS}_2\) is a colorless, volatile liquid employed as a solvent in manufacturing rubber and other organic materials.
• \(\text{S}_2\text{Cl}_2\) is formed when \(\text{CS}_2\) reacts with chlorine, important for synthesizing other sulfur compounds.

These reactions highlight sulfur's versatility in forming various environmentally and industrially significant compounds from methane and other simple chemical reactions.