Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
A solution is a homogeneous mixture formed when a substance (solute) is dissolved in another substance (solvent). The relationship is expressed as: .
Solute: The substance that gets dissolved (e.g., salt or sugar ).
Solvent: The medium in which the solute dissolves (e.g., water ). Water is known as the 'Universal Solvent'.
Temperature: Dissolution happens faster at higher temperatures. Heating the solvent () increases the kinetic energy of its molecules, allowing them to break down solute particles more rapidly.
Stirring/Agitation: Stirring helps the solute particles spread quickly through the solvent, bringing fresh solvent molecules into contact with the solute.
Particle Size (Surface Area): Smaller particles (like powdered sugar) dissolve faster than large chunks (like sugar cubes) because more surface area is exposed to the solvent molecules.
Saturated Solution: A solution in which no more solute can be dissolved at a given temperature.
📐Formulae
💡Examples
Problem 1:
Why does a teaspoon of salt () dissolve faster in a glass of hot water () compared to a glass of cold water?
Solution:
The rate of dissolution is higher in hot water due to increased thermal energy.
Explanation:
In hot , the molecules move with higher speed and hit the crystals with more force and frequency, breaking the ionic bonds faster than in cold water.
Problem 2:
If you have 10g of sugar crystals and 10g of powdered sugar, which one will form a solution in first?
Solution:
The powdered sugar will dissolve faster.
Explanation:
Powdered sugar has a much larger total surface area compared to large crystals. This allows more molecules to surround and interact with the sugar molecules () simultaneously.
Problem 3:
What happens to the solubility of sugar in water if you keep adding sugar until it starts settling at the bottom?
Solution:
The solution becomes a 'Saturated Solution'.
Explanation:
When the solvent molecules () are completely occupied holding solute particles, no more space is available for additional solute. This state is called saturation.