Question

A ______ is dissolved in a solvent. a. molecule b. solute c. salt

Short answer

b. solute

Step-by-step solution

Understand the Question

The question is asking for a term that describes what is dissolved in a solvent during the process of making a solution. There are three options given: a molecule, a solute, and a salt.

Recall Definitions

A molecule is a group of atoms bonded together, which can be part of a solute but is not limited to being dissolved. A solute is a substance that gets dissolved in a solvent to form a solution. A salt is a specific type of solute that consists of ionic compounds.

Identify the Correct Term

The term that universally describes a substance being dissolved in a solvent in the process of creating a solution is the 'solute.' A salt is a specific example of a solute, while 'molecule' is not specific to dissolution.

Choose the Answer

Based on the definitions and the requirement for a general term, the correct answer is 'solute' because it is the general term for any substance that is dissolved in a solvent.

Key concepts

Solvent

A solvent is a key component in the formation of a solution. It is the substance that dissolves another substance, known as the solute. Solvents can be various liquids, gases, or even solids, but are most commonly liquids due to their ability to dissolve many substances.
Common examples of solvents include:

• Water - Known as a universal solvent due to its ability to dissolve more substances than any other liquid.
• Acetone - Widely used as a solvent in nail polish removers and some types of paint thinners.
• Ethanol - Used in alcoholic beverages and as a solvent for various chemicals.

The effectiveness of a solvent often depends on its polarity, which means how molecules are distributed in terms of electric charge. Polar solvents like water can dissolve ionic and other polar substances well, while non-polar solvents work better with non-polar solutes.
When mixing, the solvent molecules surround the solute particles, helping them to disperse and dissolve, often resulting in a homogeneous mixture.

Solution

A solution is a homogeneous mixture formed when a solute is completely dissolved in a solvent. This means that the composition is uniform throughout, with no visible separation between the different components.
Characteristics of a solution include:

• Uniformity - The mixture is consistent at the molecular level.
• Stability - Solutions are stable and do not separate out over time under normal conditions.
• Transparency - Solutions are often clear, with no particles visible to the naked eye.

Solutions come in various forms, including:

• Solid solutions, like alloys, which are mixtures of metals.
• Gaseous solutions, such as air, which is a mixture of gases like nitrogen and oxygen.
• Liquid solutions, where a solute is dissolved in a liquid solvent, such as sugar in water.

In chemistry, understanding the concentration of a solution, which is the amount of solute per unit volume of solvent, is crucial. This determines the strength of the solution and can be expressed in various units like molarity, molality, or parts per million (ppm).

Molecule

A molecule is the smallest unit of a chemical compound that retains its chemical properties. It consists of two or more atoms bonded together. Molecules can be highly diverse in size and complexity and they form the basis of everything around us.
Key points about molecules:

• They can be composed of the same type of atoms, such as O₂ (oxygen gas), or different types, like H₂O (water).
• Molecules exhibit specific geometric shapes, which affect their chemical behavior and interaction with other substances.
• The strength and type of bonds within a molecule (covalent, ionic, or hydrogen bonds) affect its properties and interactions.

While molecules are fundamental building blocks, not all molecules are suitable as solutes. This depends on their nature and the solvent involved. For instance, glucose (a molecule) dissolves readily in water due to its polar nature, but non-polar molecules like oil do not.