Dissolving

 

Dissolving

To understand dissolving, we must first know what a solvent, a solute and a solution are.

 

• Solute: Substance that dissolves to form a solution.
• Solvent: A substance that can dissolve other substances to form a solution.
• Solution: A mixture of one or more solutes that are dissolved in a solvent.

 

During the dissolving process, solvent and solute particles collide. The solvent particles move around and slowly surround the solute particles until they are mixed well in the solvent.

For example, salt dissolves when it is stirred into water.

 

 

 

In the saltwater solution, salt is the solute and water is the solvent. The solute and solvent blend together in a solution.

There is a maximum amount of solute that can dissolve in a certain amount of solvent. When the solute cannot dissolve anymore, the mixture is called a saturated solution.

 

 

Conservation of Mass

The solute does not vanish when it dissolves. For example, if 25 grams of water has 1 gram of salt dissolved in it, then the mass of the saltwater solution would be 25 grams + 1 gram = 26 grams.

 

🧪 Knowledge Check: Dissolving

Test your understanding of solutions, mixtures, and the dissolving process based on the lesson content.

1. In a mixture of salt and water, which substance is the 'solvent'?

• Salt
• Water
• The salty water

2. If 10g of sugar is dissolved in 100g of water, what will the total mass of the solution be?

• 90g
• 100g
• 110g

3. What term is used to describe a substance that CANNOT dissolve in a solvent?

• Soluble
• Insoluble
• Saturated

4. A solution is described as 'saturated' when:

• No more solute can be dissolved in it.
• The solvent has completely evaporated.
• The solute is still a visible solid at the bottom.

5. When a solute dissolves, what happens to its particles?

• They disappear and no longer have mass.
• They spread out and fit into the spaces between the solvent particles.
• They turn into gas and escape from the liquid.

Click to Reveal Answers

1. Water (The liquid that does the dissolving).
2. 110g (Mass is conserved: 10g solute + 100g solvent).
3. Insoluble (Examples include sand in water).
4. No more solute can be dissolved (The limit of solubility has been reached at that temperature).
5. They spread out between solvent particles (They are still there, which is why the mass remains the same).

 

Summary:

 

• A solution is formed when a solute mixes with a solvent.
• If a substance can mix with a solvent, it is soluble. If it cannot mix, it is called insoluble.
• Heating, stirring and using small pieces are all ways to make dissolving faster.