Problem 42 - Chemistry Principles and Practice

Question

Which of the following mixtures is a solution? (a) Wood (b) Champagne (c) Salt water (d) Cloudv tea

Step-by-Step Solution

Answer

Champagne and salt water are solutions.

Step 1: Understand the Definition of a Solution

A solution is a homogeneous mixture of two or more substances where the solute is completely dissolved in the solvent. The mixture appears uniform throughout and no particles are visible.

Step 2: Analyze Each Option

Let's review each option to check if it meets the criteria of a solution. (a) Wood: Wood is a composite material, made up of various components like cellulose and lignin. It's not uniform throughout, so it's not a solution. (b) Champagne: Champagne is a mixture of carbon dioxide (gas) dissolved in liquid, making it homogeneous and therefore a solution. (c) Salt water: Salt water is a mixture where salt is completely dissolved in water, creating a uniform solution. (d) Cloudy tea: Cloudy tea suggests particles that are not fully dissolved, indicating a suspension rather than a solution.

Step 3: Identify the Solutions

Based on the analysis, options (b) Champagne and (c) Salt water are solutions because they are homogeneous mixtures with dissolved substances. Wood and cloudy tea do not fit the criteria because they are not uniform throughout.

Key Concepts

Homogeneous Mixtures

In chemistry, a homogeneous mixture is a type of mixture in which the composition is uniform throughout. This means that every part of the mixture has the same properties and appearance. Homogeneous mixtures are also called solutions when they involve substances dissolving into each other.

Key characteristics of homogeneous mixtures include:

• They exhibit a uniform appearance and composition.
• Individual components are not distinguishable by the naked eye.
• The mixture looks the same no matter how small the sample size.

Examples of homogeneous mixtures include air (a mixture of various gases), vinegar (a mix of acetic acid and water), and our step-by-step solution highlighted salt water and champagne. These demonstrate the principle of a consistent mixture where the solute is uniformly distributed.

Solute and Solvent

Solutions are formed by dissolving a solute into a solvent. The solute is the substance that is dissolved, while the solvent is the substance that does the dissolving. In any solution, the solute can be a solid, liquid, or gas, while the solvent is often a liquid, but not always.

To better understand solute and solvent:

• Solute: This is the substance that gets dissolved. In salt water, salt is the solute.
• Solvent: This is the medium in which the solute dissolves, usually present in a larger quantity. In salt water, water acts as the solvent.

The process of dissolving involves the solute's particles being surrounded by the solvent's particles, resulting in a homogeneous mixture. The effectiveness of the solvent's ability to dissolve depends on several factors including temperature, pressure, and the chemical nature of the solute and solvent.

Chemical Solutions

Chemical solutions are vital components in many processes, providing a medium for reactions and interactions between molecules. A chemical solution is characterized by the even distribution of the solute within the solvent, resulting in a stable, uniform mixture.

Consider these points about chemical solutions:

• Saturated solutions occur when no more solute can dissolve in the solvent at a given temperature.
• Concentration of a solution refers to the amount of solute present in a given quantity of solvent or solution.
• Solutions can be categorized based on the state of solute and solvent; for example, gaseous (air), liquid (salt water), and solid solutions (alloys).

Understanding these concepts helps explain why champagne and salt water qualify as solutions in our original exercise – each maintains uniform composition and stable properties, typical of chemical solutions.