Question

Define solubility.

Short answer

Solubility is the ability of a substance (solute) to dissolve in a solvent, typically measured as the concentration of dissolved solute at a specific temperature, such as grams of solute per 100 grams of solvent. Factors affecting solubility include temperature, pressure, and the types of solute and solvent involved, with the principle "like dissolves like" meaning that polar solutes are more likely to dissolve in polar solvents, and nonpolar solutes in nonpolar solvents.

Step-by-step solution

Introduce the term

Solubility is a term commonly used in chemistry that refers to the ability of a substance (solute) to dissolve in a solvent.

Describe how solubility is measured

The extent to which a solute dissolves in a solvent is typically measured in terms of the maximum amount of solute that can be dissolved in a given amount of solvent at a specific temperature. This measurement is usually presented as a concentration, such as grams of solute per 100 grams of solvent.

Provide examples of solubility

Examples of solubility include salt dissolving in water, sugar dissolving in coffee, or oxygen dissolving in blood. Some substances have high solubility, meaning they dissolve easily at room temperature (for example, table salt and sugar have high solubility in water), while others have low solubility (for example, sand does not dissolve in water).

Explain factors affecting solubility

Several factors can affect solubility, such as temperature, pressure, and the types of solute and solvent involved. For instance, with most solid solutes, solubility tends to increase with increasing temperature. In contrast, the solubility of gases in liquids generally decreases with increasing temperature. Additionally, the solubility of a substance depends on the nature of the solute and solvent, with the popular principle stating "like dissolves like." This means that polar solutes are more likely to dissolve in polar solvents, and nonpolar solutes are more likely to dissolve in nonpolar solvents.

Recap the definition of solubility

In summary, solubility refers to the ability of a substance to dissolve in a particular solvent. This property is typically measured as the concentration of dissolved solute at a specific temperature and is influenced by various factors, such as temperature, pressure, and the nature of the solute and solvent.

Key concepts

Solute and Solvent

In any solution, the solute is the substance being dissolved, while the solvent is the substance that does the dissolving. Think of it like sugar (solute) dissolving in water (solvent) to make sweetened water. The solute is typically present in a smaller amount compared to the solvent.

Solvents are often liquids, but they can also be gases or solids. For example, solid solutes can dissolve in liquid solvents, like salt in water, or even gas solutes can dissolve in liquid solvents, like carbon dioxide in soda.

Understanding the roles of solute and solvent is key to grasping how solutions form, and how they can vary based on different combinations of solutes and solvents.

Factors Affecting Solubility

Solubility is significantly influenced by a variety of factors which determine how well a solute dissolves in a solvent. Let's explore some of these factors to deepen our understanding:

• Temperature: Generally, increasing the temperature increases the solubility of solid solutes in liquids. However, this relationship is reversed for gases, which tend to become less soluble as temperatures rise.
• Pressure: This mainly affects the solubility of gases. An increase in pressure often increases how much gas can dissolve in a liquid, which is why soda is bottled under high pressure to keep the carbon dioxide dissolved.
• Nature of solute and solvent: According to the principle "like dissolves like," polar solutes tend to dissolve more readily in polar solvents, and nonpolar solutes in nonpolar solvents.

These factors interact in complex ways and are important considerations for applications ranging from industrial processes to food preparation.

Measurement of Solubility

Solubility is quantified by measuring the maximum amount of solute that can dissolve in a specified quantity of solvent at a given temperature. This is often expressed as a concentration, such as grams of solute per 100 grams of solvent, providing a clear numerical representation of solubility.

Consider, for example, measuring how much sugar dissolves in a cup of coffee. By knowing how many grams of sugar can dissolve before it stops dissolving further, we establish coffee’s saturation point.

Temperature is a critical condition to record when measuring solubility, since it can significantly influence the outcome. Thus, solubility is often expressed with reference to its corresponding temperature, such as "30 grams per 100 grams of water at 20°C."

This information is crucial for practical applications like formulating medicinal solutions, cooking, and even designing industrial chemical processes.