Chapter 2: Problem 74
Explain why the formula \(\mathrm{HCl}\) can represent two different chemical systems.
Short Answer
Expert verified
\(\mathrm{HCl}\) represents gaseous hydrogen chloride and aqueous hydrochloric acid.
Step by step solution
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Key Concepts
These are the key concepts you need to understand to accurately answer the question.
hydrogen chloride
Hydrogen chloride is a compound with the chemical formula \( \mathrm{HCl} \). It is composed of one hydrogen atom and one chlorine atom, forming a diatomic molecule. In its pure form, at room temperature and pressure, hydrogen chloride exists as a colorless gas known as hydrogen chloride gas.
This gaseous state of \( \mathrm{HCl} \), significant in various industrial processes, should not be confused with the acid version, which emerges under different conditions. Hydrogen chloride gas is known for its sharp, pungent odor and its ability to form hydrochloric acid upon contact with moisture or water.
Recognizing \( \mathrm{HCl} \) as hydrogen chloride highlights the importance of context in chemistry, where the same molecular formula can represent entirely different substances based on its state and the environment.
This gaseous state of \( \mathrm{HCl} \), significant in various industrial processes, should not be confused with the acid version, which emerges under different conditions. Hydrogen chloride gas is known for its sharp, pungent odor and its ability to form hydrochloric acid upon contact with moisture or water.
Recognizing \( \mathrm{HCl} \) as hydrogen chloride highlights the importance of context in chemistry, where the same molecular formula can represent entirely different substances based on its state and the environment.
hydrochloric acid
When hydrogen chloride gas dissolves in water, it forms what we know as hydrochloric acid. This transition from a gaseous state to an aqueous solution is crucial for its application in many chemical reactions and industrial uses. In water, \( \mathrm{HCl} \) dissociates into hydronium ions (\( \mathrm{H_3O^+} \)) and chloride ions (\( \mathrm{Cl^-} \)), a process that gives hydrochloric acid its strong acidic properties.
Hydrochloric acid is a common and powerful acid used for cleaning, in laboratories, and in the manufacturing and processing of different goods. It demonstrates the dramatic change in chemical behavior that \( \mathrm{HCl} \) undergoes due to its interaction with a solvent like water.
This ability to shift from a simple gas to a vital industrial acid underscores the diverse roles that \( \mathrm{HCl} \) can play, driven by environmental factors like solvation.
Hydrochloric acid is a common and powerful acid used for cleaning, in laboratories, and in the manufacturing and processing of different goods. It demonstrates the dramatic change in chemical behavior that \( \mathrm{HCl} \) undergoes due to its interaction with a solvent like water.
This ability to shift from a simple gas to a vital industrial acid underscores the diverse roles that \( \mathrm{HCl} \) can play, driven by environmental factors like solvation.
physical state impact
The physical state of \( \mathrm{HCl} \) affects its chemical behavior significantly. As a gas, \( \mathrm{HCl} \) remains a stable, diatomic molecule with limited reactivity unless mixed with moisture. In contrast, as an aqueous solution, it becomes hydrochloric acid, which exhibits high reactivity due to the presence of free hydrogen ions.
Gaseous hydrogen chloride can be stored and transported easily in cylinders under pressure, making it useful for processes requiring pure \( \mathrm{HCl} \) without the need for an aqueous medium.
Once dissolved in water, \( \mathrm{HCl} \) transforms entirely in its physical nature, contributing to the acidic nature and leading to a myriad of possible reactions, including its use in titration, pH adjustment, and as a reactant.
Gaseous hydrogen chloride can be stored and transported easily in cylinders under pressure, making it useful for processes requiring pure \( \mathrm{HCl} \) without the need for an aqueous medium.
Once dissolved in water, \( \mathrm{HCl} \) transforms entirely in its physical nature, contributing to the acidic nature and leading to a myriad of possible reactions, including its use in titration, pH adjustment, and as a reactant.
role of solvents
Solvents play a critical role in transforming and determining the chemical system that \( \mathrm{HCl} \) represents. With water as the solvent, \( \mathrm{HCl} \) goes from being a simple gas to an acidic solution. This transformation is a classic example of how solvents can redefine chemical properties without altering the actual chemical composition.
When hydrogen chloride gas comes into contact with water, water molecules help dissociate \( \mathrm{HCl} \) into ions, giving birth to hydrochloric acid. The solvent, in this case, does not partake in the reaction itself but facilitates the process by providing a medium for ionization.
Understanding the role of solvents helps reveal how chemical reactions are often dependent on the environment, with solvents dictating whether a chemical can be isolated as one form or participate in additional chemistry that leads to new compounds or properties.
When hydrogen chloride gas comes into contact with water, water molecules help dissociate \( \mathrm{HCl} \) into ions, giving birth to hydrochloric acid. The solvent, in this case, does not partake in the reaction itself but facilitates the process by providing a medium for ionization.
Understanding the role of solvents helps reveal how chemical reactions are often dependent on the environment, with solvents dictating whether a chemical can be isolated as one form or participate in additional chemistry that leads to new compounds or properties.
