Factors that Affect Solubility

Summary

This video explores the factors that affect solubility, including stirring, temperature, particle size, and pressure. Stirring speeds up the dissolving process, while higher temperatures help solids dissolve faster but reduce the solubility of gases. Smaller particles dissolve more quickly due to increased surface area, and pressure has little effect on solids but significantly increases the solubility of gases. The video also explains how air and carbon dioxide dissolve in water, highlighting real-world examples like fizzy drinks and the minerals in tap water. Understanding these factors helps explain why substances dissolve in water at different rates.

Takeaways

• 💧 Solubility refers to how well a substance can dissolve in a solvent like water.
• 🏖️ Sand does not dissolve in water and is therefore insoluble, while salt dissolves and is soluble.
• 🔄 Stirring a solution increases the rate at which a solid dissolves, helping substances mix faster.
• 🔥 Higher temperatures generally increase the solubility of solids in water, allowing more to dissolve.
• ❄️ Lower temperatures reduce solid solubility, which is why sugar dissolves more slowly in iced tea than in hot tea.
• 🌬️ Gases behave oppositely to solids — as temperature increases, gas solubility decreases.
• ⚛️ Smaller particle sizes dissolve faster because they provide more surface area for interaction with water molecules.
• 💨 Pressure has little to no effect on solid solubility but significantly affects gas solubility.
• 🥤 Increasing pressure increases the solubility of gases in liquids, which is how carbonated drinks retain their fizz.
• 🍾 When a soda bottle is opened, pressure is released, gas solubility drops, and the drink eventually goes flat.
• 🌊 Both solids and gases can dissolve in water — even the air we breathe (oxygen, nitrogen, carbon dioxide) partially dissolves in it.

Q & A

What is solubility?

Solubility refers to the ability of a substance to dissolve in a solvent, such as water, to form a solution. Some substances dissolve well in water, while others do not.

What happens when you stir sand into water?

When you stir sand into water, the sand does not dissolve. It simply settles to the bottom, making it insoluble in water.

Why does salt dissolve in water but sand doesn't?

Salt dissolves in water because its particles break apart and spread evenly throughout the water. Sand, on the other hand, is made of larger particles that do not interact well with water molecules, making it insoluble.

What are the four factors that affect solubility?

The four factors that affect solubility are stirring, temperature, particle size, and pressure.

How does stirring affect the rate of solubility?

Stirring increases the rate at which a solid dissolves in a liquid. It helps particles of the solid to disperse and interact with the solvent more quickly.

How does temperature affect solubility?

In general, increasing the temperature of the solution allows solids to dissolve faster and in greater quantities. However, for gases, the opposite is true: higher temperatures make gases less soluble in water.

Why do solids dissolve faster in hot water than in cold water?

Solids dissolve faster in hot water because the increased temperature causes water molecules to move faster, which allows them to interact more quickly with the solute particles, breaking them apart.

How does particle size influence solubility?

Smaller particles dissolve faster than larger ones because smaller particles have a greater surface area for the solvent molecules to interact with.

How does pressure affect the solubility of solids and gases?

Pressure has little to no effect on the solubility of solids, but it greatly increases the solubility of gases. The higher the pressure, the more gas can be dissolved in the liquid.

Why does soda lose its fizz when opened?

Soda loses its fizz when opened because the pressure inside the bottle is released. As the pressure decreases, the solubility of carbon dioxide (CO2) decreases, causing the gas to escape and the soda to go flat.