How Solubility and Dissolving Work

Summary

This video from the Science Basement explores the concept of solubility, explaining key terms like solute, solvent, and solution. Using everyday examples such as water, hot chocolate, and table salt, it illustrates how water's polar molecules interact with ions to dissolve substances. The video also contrasts true solutions with suspensions and colloids, explains why some substances like oil are insoluble, and highlights the vital role of solubility in biological and environmental processes. Viewers are encouraged to experiment at home with common ingredients to observe solubility in action, making the topic both educational and hands-on.

Takeaways

• 🌊 Solubility is the ability of a substance to dissolve in another substance and form a solution.
• 💧 A solvent is the substance that does the dissolving, such as water in hot chocolate.
• 🍫 A solute is the substance that gets dissolved, like hot chocolate mix in water.
• 🧂 When salt dissolves in water, it dissociates into sodium and chloride ions that mix uniformly with water.
• ⚛️ Water is a polar molecule with a slightly positive hydrogen side and a slightly negative oxygen side.
• 🔬 Because water is polar, it can dissolve other polar substances and ions, earning the nickname 'universal solvent'.
• 🛢️ Non-polar substances like oil do not dissolve in water because there are no charges for water molecules to interact with.
• 🥄 True dissolving happens at the molecular or ionic level, unlike suspensions or colloids where larger particles remain separate.
• 🌱 Solubility is essential for life, helping transport nutrients and remove waste in both humans and plants.
• 🌬️ Gases also dissolve in each other, such as nitrogen, oxygen, and carbon dioxide in the atmosphere.
• 🏠 Solubility experiments can be performed at home using common ingredients like salt, sugar, flour, and cornstarch to observe which substances dissolve.

Q & A

What is solubility and how is it defined?

Solubility is the ability of a substance to dissolve in another and form a solution. It combines the concepts of 'solution' and 'ability'.

What is the difference between a solute and a solvent?

A solvent is the substance that does the dissolving, while a solute is the substance that gets dissolved. For example, in hot chocolate, water is the solvent and the hot chocolate mix is the solute.

Why is water considered a polar molecule?

Water is polar because its molecular structure causes the electrons to be unevenly shared between hydrogen and oxygen. This makes the hydrogen side slightly positive and the oxygen side slightly negative.

How does water dissolve table salt at the molecular level?

Water molecules surround the sodium and chloride ions. The positive side of water attracts chloride ions, while the negative side attracts sodium ions, causing the salt to dissociate into individual ions and form a uniform solution.

Why are some substances, like oil, insoluble in water?

Oil is non-polar, so water molecules cannot interact with it because there are no charges for the polar water molecules to attract. Substances without positive or negative charges are generally insoluble in water.

What is the difference between a true solution and a suspension or colloid?

In a true solution, individual molecules or ions are completely surrounded by the solvent. In suspensions or colloids, larger particles are mixed in the solvent but not fully dissolved, so they can be seen under close observation.

Why is solubility important for the human body?

Solubility allows water in the body to transport nutrients, carry substances into the bloodstream, and remove waste efficiently, supporting vital biological processes.

How does solubility benefit plants?

Solubility allows water to transport dissolved nutrients from roots to various parts of the plant and is essential for photosynthesis.

Can gases dissolve in each other? If so, give an example.

Yes, gases can dissolve in each other. The atmosphere is a solution of gases, primarily 78% nitrogen, 21% oxygen, and 0.04% carbon dioxide.

How can solubility be tested at home or in a classroom?

By mixing common substances like salt, sugar, flour, baking soda, or cornstarch with water, you can observe which substances dissolve and which do not, helping to understand their solubility properties.

Why is water sometimes called a 'universal solvent'?

Water can dissolve many different polar substances and ions due to its polarity, making it extremely versatile as a solvent. However, it is not truly universal because it cannot dissolve non-polar substances like oil.